Youngest Celtics player ‘exceptional’ off bench in win over Bucks

When Sam Hauser went down with the back injury that’s now sidelined him for three straight games, Celtics coach Joe Mazzulla said the plan to replace one of his top reserves would vary each night.

On Monday, it included Boston’s youngest player for the first time.

Jordan Walsh saw the biggest minutes of his NBA career against the Milwaukee Bucks and earned applause for his performance in a 119-108 win at TD Garden.

“I thought Jordan played great,” Jaylen Brown said. “His minutes were exceptional for our team. He made some big-time offensive rebounds, had some big defensive possessions. Credit to him being ready. Big game, big moment for a young player playing against a potential playoff matchup. I thought he added and contributed to us getting a win tonight.”

Walsh, who spent most of his rookie season in the G League, missed two open 3-pointers in the first quarter but helped fuel a third-quarter run that broke the game open. The 20-year-old forward grabbed defensive rebounds on back-to-back Bucks possessions, then tipped in a missed Derrick White 3-pointer to put the Celtics up 87-80.

By the time Boston’s regulars exited the game, the Celtics had outscored the Bucks by 15 points with Walsh on the floor. That number dropped to plus-10 after a few late buckets by Milwaukee backups but still was tied for third-best on the team behind Jayson Tatum (plus-18) and Payton Pritchard (plus-12).

“He played well,” Jrue Holiday said. “He came in and played some big minutes against a good team. I think seeing Jordan getting out there, getting some reps, playing great even though he probably wanted to knock down a couple more shots, but you see what type of player he is. And that’s just a testament to him putting in the work, him taking his time and being able to go out there and concentrate. Again off the court, he acts the same way, very under control, and he does what he’s supposed to do.”

After Walsh’s rough showing at the Las Vegas Summer League, Mazzulla urged him to focus on the less flashy, dirty-work elements of his game. The 2023 second-round pick bought in and enjoyed a surprisingly impressive preseason, winning the end-of-the-rotation spot previously occupied by departed free agent Oshae Brissett.

The head coach didn’t call on Walsh in the first three regular-season games — the 2023 second-round pick only played in garbage time as Boston leaned more on double-big lineups in Hauser’s absence — but believed he handled his increased role well on Monday.

“I told Jordan in the locker room: I think just finding out a role and making big-time plays like that is huge,” Mazzulla said. “I thought he had a great defensive play on Giannis (Antetokounmpo) in the post, taking away his tendency, and got fouled going up for an offensive rebound. I mean, you have to win games like that, especially against good teams. Sometimes it’s going to be gritty. It’s got to be ugly. So I thought they did a good job of doing that.”