The last time Powe was in a Celtics uniform was for Game 2 of the first-round playoff series against Chicago last spring, when after tearing the anterior cruciate ligament and meniscus in his left knee, he tried to play through it, going three minutes before coming off the floor.

He had surgery in May, and at the end of the season became a free agent, wondering whether the Celtics still saw a place for him after his third ACL operation.

Cleveland made an offer (two years, $1.8 million), the Celtics decided not to, and just like that, Powe, who had won a championship with Boston in 2008, was a Cavalier. He was hurt, but he moved on.

“Everybody knows my work ethic,’’ Powe said. “I don’t know if they were questioning my work ethic or what. I felt like if I work hard and I put in the time, I’d be able to get back when I said I was.’’

After nine months of rehabbing, Powe returned to TD Garden last night with the Cavaliers, checking in at the end of the first half and finishing with 4 points and two rebounds in four minutes. The person who was likely the least surprised by Powe’s comeback was Celtics coach Doc Rivers.

“When he got hurt,’’ Rivers said, “I kept hearing people say, ‘He’ll never play again.’ I said, ‘You clearly don’t know who Leon Powe is.’ If anybody’s going to play again, it’ll be Leon.’’

Powe, who averaged 6.6 points and 4.2 rebounds in three years as a grinder off the Celtics bench, worked his way back by not missing a second, much less a day of rehab.

“Just trying to do whatever to get me better,’’ Powe said. “If it’s 10 reps, I’d do 30. They’ll tell me to relax a little bit because you can’t get it back in one day.’’

Cavaliers coach Mike Brown never thought twice about general manager Danny Ferry’s decision to bring in Powe.

“Danny signed him, said he’d be all right in February,’’ said Brown.

“I’m not a heavy thinker; I didn’t think too much. I just said great. I knew he kicked our behind when we played against him.’’

Rivers said Pierce would likely miss the next couple of games.

“We want to make sure it gets right,’’ Rivers said. “That’s one of those things where if it gets hit again, it’ll go back down the road. We want to make sure when he comes back he can play, and play at the Paul level that we know.

“Right now, the swelling is down. The good part about it is when you’re shooting, no one’s hitting it. We just want to get him out of that stage [to] where if someone hits it, we can sustain the hit. Right now, if someone hits it, it would go right back to where it was.’’

“I want to compete. I want to go out there and play,’’ said Daniels. “I just wanted to go out there and play and help the team.’’

He scored 4 points on 2 of 5 shooting, looking visibly ill in the locker room after the loss.

“He gave us everything he had,’’ Rivers said. “And I couldn’t ask more from him.’’