With Udonis Haslem watching from a hotel room in Indianapolis, barred from the arena because of suspension, forward Mike Miller stepped to the forefront of the Heat’s reserve corps by scoring 12 points, helping Miami to a series-ending win over the Pacers.

And even though Haslem returned to a standing ovation when he entered Monday’s game against the Celtics, he really wasn’t needed as Miami cruised to an easy win.

Haslem’s true return came Wednesday.

Miami’s 115-111 overtime victory over the Celtics in Game 2 of the Eastern Conference finals wouldn’t have come without Haslem’s play in the second half and overtime, as he scored all 13 of his points after halftime to pick up his first postseason double-double since 2009.

Haslem played most of the second half and helped Miami come back in both the third and fourth quarters before scoring four key points in overtime — plus, LeBron James’ cleaned up on Haslem’s miss to tie things at 105.

Miller, Haslem’s teammate at Florida, also contributed as he hit a three-pointer early in the fourth quarter (off a Haslem pass) to help the Heat put some much-needed distance between it and the Celtics. At that point, Miami had a seven-point lead.

The Celtics turned things around in the fourth, with Haslem and Miller both missing shots in the quarter. They weren’t alone, however. After Miller’s 3-pointer 52 seconds into the fourth, Miami had only made one other field goal (Mario Chalmers) before Shane Battier sank a 3-pointer with 2:18 left to tie things at 94.

Haslem played much of the fourth and gave the Heat a boost with 1:08 left when his jumper off a feed from Dwyane Wade gave Miami a four-point lead. With 2:42 left in overtime, Wade found his old buddy again as Haslem drained a jumper to pull the Heat within a point at 104-103. Later in the overtime session, Haslem dunked to give Miami its first lead with 1:27 left.

Miami needed Haslem to take a more active role in the third when, after a quiet start, he was pulled into duty early in the quarter when Joel Anthony picked up his fourth foul. Miami trailed by nine at that point, but Haslem quickly made an impact.

Soon after Wade scored to cut the deficit to seven, Haslem hit a baseline jumper from 18 feet out to make it a five-point game. Haslem ended with seven points in the third period — he had none prior — and Miami took a six-point lead into the fourth.

Miller, who scored 10 points in the first five games of the Pacers series before getting 12 in Game 6 alone, has been one of Miami’s first forward options off the bench.

Wednesday, Miller came onto the court for the first time with 4:13 left in the quarter and promptly drained a 20-foot jumper.

Miller didn’t have the best numbers on Wednesday — he ended with seven points on 3-of-7 shooting, including 1 of 4 from downtown — yet perseveres despite the pain of playing. What’s wrong with Miller probably isn’t the best way to ask the question. What isn’t probably is.

Injured for much of his two seasons in Miami — you name the injury, he’s probably had it — Miller is getting used to playing through the pain.

“At this time of year, everyone is playing through something. Everyone has something that doesn’t feel right,” Miller said. “In the best-case scenario, we have 30 days left. You can make it through anything in 30 days. That’s my motivation right now. Hopefully something good comes out of it.

“You don’t want to miss these games for any reason. There are no excuses. I’m not going to look back on this and know I didn’t play. I’ve been on the other side of this where you just want to make the playoffs. Now I’ve got a chance with this team. You have to enjoy it. This is a great group to play with. We’re here for one reason — that really makes it fun.”