NBA

Knicks ousted from playoffs by Celtics; heat’s on D’Antoni

REJECTION: Jermaine O’Neal and the Celtics swatted away Carmelo Anthony and the Knicks once and for all yesterday in a 101-89 series-clinching win at the Garden. (
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The next time the Knicks grace the Garden, half the arena will be transformed with a new lower bowl and the franchise could have a new president and coach.

Because of a knee strain, a pulled back muscle and an utter lack of depth, the Knicks next season still will be looking for their first playoff win since 2001. Meanwhile, the futures of team president Donnie Walsh and coach Mike D’Antoni remain unclear.

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The Knicks’ rollercoaster campaign is over. Despite a courageous performance by Amar’e Stoudemire, who elected to play despite a pulled back muscle, the Celtics ambushed the overmatched Knicks 101-89 at the Garden to close them out in a sweep.

The Garden crowd gave the Knicks a standing ovation in the final seconds after their second-half comeback that saw them slice a 23-point third-quarter deficit to four in the final period.

But what that means for D’Antoni, who has one year left on his contract, is unclear after neither Carmelo Anthony nor Stoudemire gave him an endorsement following the loss.

Anthony was particularly lukewarm, and did not mention D’Antoni by name.

“It’s a long summer,” Anthony said when asked if he wanted D’Antoni back. “As far as the players go on the team or coach situation, I’m pretty sure the front office will handle it to the best of their ability. They have one of the greatest front offices in the NBA, so they will do their job. I’ll let them handle that.”

Anthony went on to say that he, Stoudemire and Chauncey Billups will meet with owner James Dolan and Walsh about making the Knicks “not just a playoff team but a championship-caliber team.” Anthony did not mention D’Antoni as part of the summit.

Since arriving, Anthony has talked periodically about his big adjustment to D’Antoni’s system and questioned the coach’s defensive scheme after a loss in Indiana. He is represented by the super agency CAA, which also handles Kentucky coach John Calipari and superstar point guard Chris Paul. The Knicks did not plan to make Walsh or D’Antoni available to the media today, when the team convenes for exit meeting, as is customary.

Asked about D’Antoni’s return, Stoudemire, who supported the coach all season, surprisingly evaded the issue, only saying he’s been “great my whole career.” However, a source familiar with Stoudemire’s thinking said Stoudemire supports D’Antoni and would do any lobbying privately.

D’Antoni raved about Stoudemire’s season and finish after the star forward played 44 minutes despite major reservations about suiting up because of a pulled back muscle.

Though he missed his first nine shots, Stoudemire was a ton more active than he was in the Game 3 debacle Friday, a warrior in crashing the boards and barreling to the rim in the second half. He finished with 19 points on 5-of-20 shooting and 12 rebounds. He struggled to find his jumper or elevation because of the back and committed five turnovers.

“Amar’e started the year the way he ended it — all heart,” D’Antoni said. “He gave it all. He was unbelievable as a leader and as a person. I would think with him and Carmelo going forward, the Knicks are in good shape.”

Anthony scored 32 points on 10-of-24 shooting, but scored just five points in the fourth quarter, unable to keep alive the rally keyed by the frantic pace set by third-string point guard Anthony Carter (11 points on 5-of-7 shooting and four assists in 23 minutes).

“I am excited about the upcoming seasons,” said Anthony, who shot 36 percent in the series and was eliminated in the first round of the playoffs for the seventh time in eight years. “We proved to a lot of people, shorthanded or not, that we are going to compete night in and night out.

“We got respect from a lot of people, but it’s the first step to something great to come.”

The Knicks were without Billups for the final three games after losing him to a strained left knee in the final minute of Game 1. Stoudemire missed the second half of Game 2 and played at much less than 100 percent in Games 3 and 4.

“We definitely feel a little cheated,” Bill Walker said. “We didn’t have our team at full strength.”

Stoudemire said the series could have been different with a healthy team.

“I think we would have had a better run,” he said.

Depth was not the Knicks’ strong suit after the roster-revamping Anthony trade.

“Boston is a better team than we are in every sense of the word,” D’Antoni said. “We just didn’t get quite enough from a lot of people.”

marc.berman@nypost.com