BOSTON — Kyrie Irving has said his role, at the age of 26 on a team of mostly younger players, is changing.

The Boston Celtics guard spoke Monday night of his desire to improve in an area that has been considered maybe the only weakness in his game – defense.

“I just feel like I’m asking myself to do a lot more on the defensive end this year. I think the next 8-10 years – God willing I’m able to play that long – I want to take that challenge on that end, and in order to do that,” he said following the Celtics’ 93-90 loss to Orlando, “you have to be in phenomenal shape. I think that even for me, coming to the realization that I’ve coasted certain times on the defensive end throughout seasons and haven’t taken the challenge.

“This year, I want to take that challenge and stop my man and lead these guys on the defensive end first. We all feel good when we get out in transition and get easy baskets and everyone’s playing hard. That for me is a challenge, just internally, that I’m taking on. But as far as figuring how I fit in with other guys, it’s going to take a little while. But I don’t want anybody else to stop being who they are. It’s going to (require) a lot of commitment and sacrifice and understanding of that for us to be great going forward. So like I said, it’s the fourth game, but obviously, I’ve been analyzing this for a little bit.”

• Gordon Hayward missed Boston’s win last Saturday against New York because of soreness in his surgically repaired ankle – a sensation he admits will probably continue as he comes back from a year away from the game. But based on his 11-point, 4-for-8 performance Monday against Orlando, the forward appears to be regaining his rhythm.

“I mean, there’s soreness in my ankle every time I play right now,” he said. “I think there will be soreness for a little while. I think it was something we planned on doing that. That’s why I’m on a minutes restriction as well. They don’t want any overloading issues, so there is some load management stuff basically.”

Hayward added that he does not expect a restriction on playing in back-to-back games.

• Though Aron Baynes missed the loss to Orlando, the Celtics backup center’s right hamstring injury doesn’t appear to be a long-term issue, with Coach Brad Stevens calling Baynes’ work on a treadmill “encouraging.”

NUGGETS: Forward Will Barton underwent surgery to fix core and hip muscle injuries and will be re-evaluated in six weeks.

Barton was carted off the floor Saturday night after he said he felt something pop against Phoenix.

BULLS: Point guard Kris Dunn will miss four to six weeks because of a sprained medial collateral ligament in his left knee.

TUESDAY’S GAME

PISTONS 133, 76ERS 132: Blake Griffin scored a career-high 50 points and had the winner after he was fouled on a driving layup with 1.8 seconds left as Detroit topped visiting Philadelphia in a wild overtime thriller.

JJ Redick’s four-point play with 5.6 seconds left in overtime set up Griffin’s dramatics, while Joel Embiid, who had 33 points and 11 rebounds, missed a potential winner at the buzzer.