He rushed up the sideline by the scorer’s table, choking the life out of his legal pad, when he spotted a play he had seen the Spurs run on film.

“Ginobili’s coming up top!’’ he yelled.

Manu Ginobili indeed curled to the top of the arc.

“Pass! Pass!’’ Frank yelled.

Tim Duncan dropped a pass to Ginobili. Frank hunched over, knowing what was going to happen next. Ginobili twisted wildly for a layup that put the Spurs up, 42-37, in the second quarter.

“That’s from I don’t even know the hours [of film],’’ said Celtics coach Doc Rivers, after his team rallied for a 107-97 win.

But all along the Boston bench, senses were heightened. The Celtics had slogged through March, slumps and skids weighing them down as they lost games to lesser teams and lost their grip on first place in the Eastern Conference.

A battle with the league’s best team was a smelling-salt game for the Celtics, who started to doze off at the wheel.

“If you don’t come in here and play, man, they’ll blow [you] out, period, point blank,’’ Garnett said. “We saw what they did to the Heat [30-point win]. We saw what they’ve been doing practically all year.’’

The Celtics didn’t have to ask if the Spurs were going to dial up the intensity to playoff levels. The fact that Duncan, Ginobili, Antonio McDyess, and Tony Parker all sat out Monday’s loss to Portland was as good a sign as any. They were resting up for a prize fight with the Celtics.

The Celtics responded with their fifth straight win at the AT&T Center.

“We knew they rested their stars and they were preparing for this game,’’ Garnett said. “We took that personal. They’re the best team in the league. If you don’t come in here and play, they’ll treat you as if you were the worst team in the league.’’

Every basket felt like a power punch. Every shot felt like a momentum shifter. Every timeout huddle felt like a turning point.

With 2:21 left in the third quarter, the Celtics had taken the lead and were trying to assume permanent control as Paul Pierce huddled with a mix of reserves.

He looked at Delonte West, Jeff Green, Von Wafer, and Jermaine O’Neal (who was making his return after missing more than two months after arthroscopic knee surgery), and told them, “We’ve got to scrap. Let’s scrap. Every loose ball. We’ve got to get to it.’’

After the Spurs controlled the glass in the first half (26-23, 8-4 offensive), the Celtics fought back in the second (20-17). After giving up 15 second-chance points in the first half, the Celtics held the Spurs to just 3 in the second. And after turning the ball over six times in the first half, the Celtics forced the Spurs to cough it up seven times.

O’Neal tipped offensive rebounds. Wafer and West ripped down rebounds. Meanwhile, the Spurs were firing cannonballs into their own ship, taking 29 3-pointers and knocking down just eight.

The Celtics, who have struggled on the road against Western Conference teams, swept the season series with the Spurs, who lost their fifth straight overall for the first time in 14 years.

It was a regular-season game with a playoff atmosphere and the Celtics treated it that way.

“There’s certain teams when you play, they have the exact same aspirations that we have,’’ Rivers said. “So when you play a team like that, you really want to play them. That’s just human nature. When we play Miami and the Lakers and Orlando and Chicago, it’s the same way.’’

Pierce, who had been slumping, flirted with a triple-double (21 points, 11 rebounds, 7 assists). Rajon Rondo had fallen into his own funk but had somewhat of a breakthrough, finishing with 22 points (11-of-20 shooting) and 14 assists.

“This is a good place to try to gather some momentum,’’ Pierce said. “You’re talking about the team with the best record and the best home record. What better place to get back on track than here?’’

If marquee matchups are the antidote, the Celtics have road games against Chicago and Miami left on the schedule, potential shocks to the system before the playoffs start.

“It was a good, intense game,’’ Rivers said. “It’s nice to have some of those in the regular season.’’

Julian Benbow can be reached at jbenbow@....

Pierce felt the need yesterday morning to call out himself and his teammates, demanding improvement, and the Celtics produced in their 107-97 win over the Spurs last night at the AT&T Center. The Celtics have little concern about the schedule and are shifting more attention to the postseason. The regular season ends in less than two weeks, and they are playing their worst basketball of the season. That’s a combination that could lead to an early summer vacation.

While Kevin Garnett is the unquestioned spiritual leader of the team, Pierce is the captain, and the Celtics seemingly have been too consumed with the trade deadline activity and the injuries to Shaquille O’Neal and Jermaine O’Neal to fully concentrate on the last 20 games.

“The guys know what’s at stake and I just tried to reiterate that, especially with the season winding down and the playoffs around the corner,’’ Pierce said before the shootaround. “I just let everybody know how important these games are.

“At this point in the season, we should be playing our best basketball and we’re not. I don’t know if it’s we’re looking ahead to the playoffs or what, but we’ve got to understand that these games are important as far as building, and that’s what I’m trying to reiterate.’’

Pierce played with a passion not seen in weeks, and his teammates followed. After getting burned for layups, Rajon Rondo took his matchup with Tony Parker personally, producing his first 20-plus-point, 10-plus-assist game in four months. He was especially motivated after Ray Allen chewed him out for focusing on a non-call and allowing Parker to score a layup leading to a 3-point play.

Garnett shot the ball with confidence, and scored a victory in his duel with Tim Duncan. Pierce tallied 21 points, 11 rebounds, and 7 assists in one of his better performances of the season. In one critical possession, Pierce sliced through two Spurs to rebound his own miss and score a putback for a 97-87 lead with 2:49 left.

“I just tried to go out and lead by example,’’ Pierce said afterward. “I’ve just got to continue to lead this team the way I lead and hopefully we can get back on track.’’

Meanwhile, the Celtics’ defense, after being staggered in the first quarter, limited the Spurs to 41 percent shooting over the final three frames.

The Celtics are trying to avoid defensive pitfalls similar to late last season, when they lost seven of their final 10 games. Opponents were scorching the uninterested Celtics to embarrassing measures. In those 10 games, Manu Ginobili scored 28 points, Kevin Durant 37, Aaron Brooks 30, LeBron James 42, Danilo Gallinari 31, Andray Blatche 31 and Derrick Rose 39.

Those poundings occurred over 17 days, but the Celtics managed to right themselves quickly enough to reach the NBA Finals. Pierce has no intention of resting on laurels or relying on recent history. There are distinct differences between last year’s team and this year’s.

“We believe we can [make a run] like we did last year, but at the same time we didn’t have seven new players, either,’’ Pierce said before the game. “It’s a little different situation.

“We had guys who were there all year long. We didn’t have any trades. We had the same guys in the locker room, whereas now we have different guys and we try to get them to understand what it takes, and in doing that it starts for the rest of these games.’’

The Celtics went through an extensive practice here Wednesday, and coach Doc Rivers was hardly concerned about tiring out his team for the back-to-back set with the Spurs and Hawks. While the No. 1 seed in the Eastern Conference becomes more unlikely, and the Celtics may even fall to third because of Miami’s advantageous schedule, they are tired of blaming the absence of the O’Neals and the arrival of the newcomers for their slump.

Like many teams who have had success, the Celtics have gone through stretches of boredom. How else to explain losses to Memphis, Charlotte, and Indiana? How else to explain the offensive ineptitude and defensive breakdowns?

Pierce noticed that, and he viewed the aftermath of the 107-100 loss to the Pacers as an opportunity to challenge himself and his teammates.

When asked if he planned to assert himself earlier in games, Pierce said, “Nah, I don’t pre-plan my games. I just go with the flow. I just go into the game like the ocean — whatever direction it’s going, I just go with it.’’

Rivers is not convinced Pierce’s words will have a positive affect. He wants to see it in the players’ actions.

“You knew Paul would [respond] because when you speak up you have to be the one,’’ Rivers said. “I thought Paul clearly carried us in the early going. When Kevin went out [with foul] trouble and we needed scoring, it was Paul. Early in the game, he took it over for us and that’s what we can do. That was wonderful.’’

Gary Washburn can be reached at gwashburn@....

“He’ll be back in two weeks.’’

“He’ll be back after the All-Star break.’’

“He’ll be back in a week.’’

“He’s coming with us on the next road trip.’’

Twenty-six games later, O’Neal is still sidelined.

Yesterday, Celtics president Danny Ainge and coach Doc Rivers tried a different approach, specifying possible dates for the 39-year-old center’s return.

Ainge told WEEI that O’Neal will play either Sunday against Detroit or Tuesday against Philadelphia.

Rivers added caution to the optimism. “We’re hoping,’’ he said.

Having seen one general return date after another get pushed back, Rivers didn’t find much to lose in getting his hopes up again.

“The other way hasn’t worked,’’ Rivers said. “So, yeah, he’s playing Tuesday. What the hell? I tried it the other way. It hasn’t worked, so let’s jinx him or do something. We need him back.’’

O’Neal had shown signs of improvement as he traveled with the Celtics to Houston, New Orleans, and New York, but when the team returned home last week, he was back in a walking boot and had taken a cortisone shot. But Rivers said O’Neal was running back in Boston while the team was making its last extended road trip of the season.

On his weekly appearance on WEEI, Ainge said, “I was just with Shaq, we were just working out down in Waltham. Shaq is either going to play Sunday or Tuesday.’’

Even if O’Neal does return, it’s unknown how much he can contribute. He has averaged 9.3 points, 4.3 rebounds, and 20.7 minutes in 36 games this season.

“Who knows how well he can play?’’ Rivers said. “I don’t know that answer.

“The good thing with him is that he’s still big and strong. The good thing is that it’s not like he’s a focal point offensively.’’

Without Shaquille O’Neal and Jermaine O’Neal, the Celtics have lacked the size that made them the league’s most imposing team at the start of the season. The problem became more pronounced once Kendrick Perkins was traded to Oklahoma City.

Jermaine O’Neal returned to the lineup last night after missing more than two months following arthroscopic knee surgery.

Krstic injures knee Nenad Krstic will have an MRI on his right knee tomorrow after the joint appeared to bend backward with 2:19 left in the second quarter of the Celtics’ 107-97 win over the Spurs last night.

Krstic left the game and did not return, and Rivers said the center won’t be available for tonight’s game against the Hawks in Atlanta or Sunday’s tilt against the Pistons in Boston.

“He’s out obviously this weekend and an MRI,’’ Rivers said. “That’s as far as I’m going to go.’’

The Celtics acquired Krstic and Jeff Green in the deadline trade that sent Perkins and Nate Robinson to Oklahoma City. Krstic had started every game since the deal.

Last night, Glen Davis was his immediate replacement, playing 32 minutes.

Jermaine O’Neal, who collected 5 points and two rebounds in 11 minutes, may see his time increase quickly.

“It’s crazy. I told him he came back right on time,’’ said Paul Pierce of Jermaine O’Neal. “We need him. We need these bodies late in the season. Hopefully, Krstic, he’s not too hurt.’’

Rondo on target The play was designed to build a human fence for Rajon Rondo to shoot over. Davis and Kevin Garnett locked arms at the free throw line, forming a soccer-like wall to give Rondo the room he needed to knock down a 20-foot jumper that made it 84-76 in the fourth quarter. “The free kick?’’ Garnett said with a laugh. “As much as I would like to take credit for that, I can’t. That’s Doc Rivers drawing it up.’’ “It looked like a wedge in football,’’ Rivers said. “It was a hilarious play in some ways.’’ The mid-range jumper has been Rondo’s Achilles’ heel, but last night he knocked down 11 of 20 shots and he was 5 of 8 on shots from 10 feet or deeper . . . Once the Celtics wrapped up practice Wednesday, Rivers caught a flight to Chicago to see his son play in the McDonald’s All-American game. Austin Rivers, who is headed to Duke in the fall, honored his father during Tuesday night’s dunk contest, breaking out Doc’s old Atlanta Hawks jersey and throwing down a windmill. “It was really cool because he didn’t tell anybody, including me,’’ Doc Rivers said.

The Celtics came out of that huddle looking sharper, and they hung 31 points on the Hawks in the second quarter. Their lead grew to 12 in the third.

“Then we kind of relaxed,’’ Rivers said.

The points in the paint (22 in the first half) disappeared. The jump shots spiked.

“That’s a sign of fatigue,’’ Rivers said. “It’s so much easier to take jump shots.’’

The battle for rebounds became one-sided, with the Hawks gobbling up as many as they could.

“We got absolutely crushed,’’ Rivers said.

And by the fourth quarter, nothing the Celtics did leading up to that point mattered. They were in the same position they’ve been in all season when it comes to back-to-backs, running on fumes down the stretch, falling to the Hawks, 88-83.

“You knew if it came down to an extra-effort, energy game down the stretch, we were going to be in trouble,’’ Rivers said. “We got in at 4:15 in the morning. They were asleep.’’

The Hawks missed 23 shots in the first half. Paul Pierce scored 14 of his game-high 25 points before the break, but missed 6 of 10 second-half attempts. The Celtics shot 5 of 17 in the fourth quarter and 13 of 38 in the second half, stalling late after a playoff-atmosphere win over the Spurs Thursday night.

“I thought we settled,’’ Pierce said. “We took a lot of jumpers there in that third quarter where we could have pushed the lead because we were getting a lot of stops all night.’’

Rivers saw the same things, the offense unraveling as the Celtics ran out of gas, the defense suffering after that.

“At the end of the game, the one-pass rule went out the window,’’ Rivers said. “I thought we took quick, bad shots. We took all jump shots, got away from the post.

“At the end of the day, they scored 26 points [in] the fourth quarter. If you’re a great defensive team, you can never allow that many points in the fourth quarter and we did.’’

The Hawks started the fourth with a 15-5 run, and the Celtics were caught in a shootout with a Hawks team that was riding the wave of three straight wins.

Rondo (13 points) and Kevin Garnett (10 points) each grabbed 10 rebounds, but the Hawks dominated the glass, outrebounding the Celtics, 52-38.

Al Horford (16 points, 15 boards) sealed the game by sneaking through a gang of Celtics in the paint and getting an all-too-easy putback to make it a 5-point difference with seven seconds left.

Jamal Crawford led the Hawks with 20 points off the bench. Joe Johnson went 4 for 20 from the floor, but knocked down 10 of 11 free throws and finished with 19 points.

There were two early shoving matches. First, Pierce shoved Johnson, taking exception to a hard foul. Then Jermaine O’Neal got into it with Zaza Pachulia after Pachulia threw a shoulder into him while walking down the floor on a dead ball.

“I don’t think it affects us,’’ Rivers said of the dust-ups. “We get into them every game. People think we’re tough, so whenever we play they feel like they have to act tough back. I don’t know if either way that’s tough. It’s all silly.’’

Pachulia capped a 15-point, 10-rebound night with a pair of free throws that made it 86-81.

“He was the toughest dude on the floor,’’ Rivers said. “Banging everybody, got offensive rebounds, kept things alive.’’

The Celtics fell to 3-10 when playing the back half of a back-to-back on the road. They also fell to third place in the Eastern Conference behind Chicago and Miami.

“To me, it’s not about the back-to-backs,’’ Rivers said. “To me, everything is habit-forming, for the new guys especially, and for our veterans. [Thursday night] you saw that spirit, that’s nice, and today you saw the exact opposite. That can become a habit, too. We are just going to have to get out of it.’’

Julian Benbow can be reached at jbenbow@....

In a 2 1/2-hour period, NBA fans observed why the Celtics could go to the NBA Finals and why they could lose in the first round. Their apparent disinterest has sparked a lack of execution. Old guys, except if you are Dominique Wilkins, can’t turn it on like they used to.

The Celtics are waiting for consistency to return. And in the interim, they are losing games they should win. They finished this important four-game road trip a pedestrian 2-2 with blown fourth-quarter leads against the Pacers and Hawks.

Those young teams no longer fear the Celtics. The aura is officially gone. In past years, teams trailing Boston by double digits would simply fold; now they view the deficit as surmountable. Opposing teams still celebrate wins over the Celtics as if they have clinched division titles. Countless times you read the term “one of the biggest wins of the season’’ when describing a lesser team’s triumph over the Celtics.

These results shouldn’t come as such a surprise anymore. This team is running out of gas, especially in second games of back-to-back sets. But this defeat was inexcusable because the Celtics spent the third quarter toying with the Hawks, more interested in entertaining the crowd with picturesque fast-break baskets — when they didn’t have numbers — than slowing the ball and pounding it into the paint.

In the fourth quarter, when the Celtics produced a listless 15 points, they tallied just 6 of those in the paint, missed 12 of 17 shots, and allowed the Hawks six extra possessions because of their refusal to block out on rebounds.

Doc Rivers appears even more distressed than usual and tried to protect his players, claiming fatigue. But the Celtics had two days off before their victory Thursday in San Antonio and Rivers used 10 players last night, including Jermaine O’Neal, who grabbed just one rebound in 16 minutes. The fact is the Celtics are a disjointed group and have become more of a tease than actual threat to win the Eastern Conference.

Teams such as Chicago, Miami, Denver, and the Lakers have come to Atlanta and pounded the Hawks with little resistance. And the Celtics were putting on a similar show, but absent-mindedly forgot everything that earned them such third-quarter status.

“We’re concerned about playing well and better on a consistent basis,’’ forward Kevin Garnett said. “I don’t know what the other guys are thinking, but right now the focus is trying to get a consistent level of play on a consistent basis.

“We’ve got to continue to work. We are either going to quit and go home or continue to get better. We have no history of quitting, so that’s what we’re going to do.’’

But how? The Celtics have practiced harder, they have taken days off, they have waited for good health, Danny Ainge has fortified the bench. And still they can’t string three or four wins together as they did earlier in the season.

It’s a helpless feeling for Rivers, who finally believed his team had regained its confidence and thirst for execution after the San Antonio win. But now that victory may be considered just catching a slumping team at the right time, since the Spurs lost again last night.

There are seven games left, enough time for the Celtics to get back what they have owned for the past four years. But it’s definitely time to start considering whether this team has lost its killer instinct. Would they rather play up to the Atlanta crowd than grind out a win over the Hawks?

The answer last night was yes.

“I thought in the middle of the third quarter we got loose,’’ said Rivers, whose team led, 60-48, with 6:51 left in the third. “It’s the same prescription for back-to-backs. We had a chance to go from 11 up to 18 up in my opinion. We took horrible shots on one end and became lax on the other end and it became a game. When we gave up that lead [in the third quarter], you knew it was coming.’’

And Rivers made an astute observation about the second half, revealing that when he called halfcourt sets, the Celtics’ big men floated to the perimeter and settled for jump shots.

One of those culprits was Glen Davis, who ignored the paint and launched eight jumpers, hitting a desperation 32-footer.

Davis took three shots in the paint and made them all.

That pretty much sums up the Celtics’ stubbornness.

Gary Washburn can be reached at gwashburn@....

Lacerte told him, “You’re looking at 15-20 minutes your first game.’’

“That was kind of new news,’’ O’Neal said. “I didn’t know.’’

O’Neal played 11 minutes, giving the Celtics size and defense. But with Nenad Krstic injuring his right knee, whatever plans the Celtics had for easing O’Neal back into the lineup are officially scrapped.

O’Neal logged 16 uneventful minutes in last night’s 88-83 loss to the Hawks, missing his only field goal attempt, scoring just 1 point, and grabbing a single rebound.

Krstic remained with the team yesterday after sustaining the injury in the second quarter against the Spurs and will have an MRI today.

“They don’t want to guess,’’ Rivers said. “We’re just going to wait.’’

Sasha Pavlovic, Krstic’s best friend on the team, said Krstic showed concern when he talked about the injury.

“He’s worried but hopefully it’s nothing,’’ Pavlovic said. “From his experience, he said it doesn’t look that bad. He’ll know more in the morning. Hopefully it’s nothing. We need him on this team.’’

O’Neal expects his minutes to increase with Krstic’s absence, but said there was no way to work himself back slowly with just seven games left in the regular season.

“Now I’m looking at having to play a little bit more minutes, that’s probably the difference right now,’’ O’Neal said. “But at some point I’m going to need more minutes. So in these seven games that we have left I welcome the challenge. At some point I’m going to have to play an extended period to really test everything, but I feel comfortable with whatever Doc has for me.

Another missing big man, Shaquille O’Neal, could return tomorrow against the Pistons or Tuesday against the 76ers.

“There’s no easing anyone in now,’’ Rivers said. “The bottom line is, if you can play now and we can’t practice, we’re going to play you. Right now we have no choice. When Shaq comes back, he’s going to play. I don’t care if he hasn’t practiced, we’re just going to play him. That’s what we did with J.O., we don’t have a choice. It’s not like we have a bunch of time to get guys ready.’’

Taking aim Every so often, Celtics president Danny Ainge will walk up to Rajon Rondo and say, “Let me talk to you for a second.’’

He hadn’t done it in a while, but a few days ago, Ainge pulled Rondo aside and dropped a stat in his ear. He told Rondo that on shots between 6 and 23 feet, Rondo shoots 41 percent, a clip better than some of his peers at point guard.

Rondo took a season-high 20 shots Thursday night, making 11. He was 5 of 8 on attempts of 10 feet or longer. Last night, he finished 6 of 15 from the floor.

“He mentioned some other names of guys that shot a lower percentage from 6 to 23. So I’m fine with taking the shot,’’ Rondo said. “I guess it’s just emphasized that guys lay off of me and I don’t shoot them as much because I look to pass first.’’

Rivers was happy to see Rondo shoot himself out of his slump, considering it a mental process that all players go through.

“I thought when he was struggling it was great for him,’’ Rivers said. “I thought it was another phase that you go through as a player. The physical phase and the mental phase and it was just another one that he had to fight through. It’s good.’’

Cowens chimes in Celtics legend Dave Cowens filled in for Tom Heinsohn on last night’s Comcast Sportsnet telecast.

The trade that sent Kendrick Perkins and Nate Robinson to Oklahoma City for Krstic and Jeff Green has received mixed reviews and produced mixed results, but Cowens said the deal allowed the Celtics to stay in the hunt.

“I’m sure other teams have had to go through changes where key guys have had to go out, but the way I see it, they only lost one key guy,’’ Cowens said. “And he basically forced Danny’s hand based on contract talks and all the other different things.

“Everybody else, there were a couple of young guys, but the other two guys were hurt and they got able bodies back. You got guys that are playing so I think it was a masterful trade, personally. It kept them in the hunt. It could have deep-sixed them, but it kept them in the hunt.’’

Julian Benbow can be reached at jbenbow@....