Celtics may continue to bring Robert Williams off the bench indefinitely

“I think it just depends on what’s best for our team at the time, and what’s best for him,” Mazzulla said. “We’ve fluctuated the starting lineup a little bit throughout the year, which I think has given us some flexibility. But we’ve found some consistency in what we have now and I think it’s just a matter of it if makes sense, we’ll do it, and if it doesn’t, we won’t.”

Williams missed the season’s first 29 games after undergoing a September maintenance surgery on his left knee. It was expected that he’d come off the bench with a minutes restriction upon his return. But Mazzulla’s response Tuesday was the first indication that Williams could actually remain a reserve for the rest of the year.

When Jaylen Brown was asked about this possibility after Boston’s win over Houston, he appeared surprised and said it was the first he had heard of it. Williams said Mazzulla talked to him about coming off the bench prior to his return, but it was unclear whether Mazzulla expressed that it could be a longer-term plan.

“I’m a team player,” Williams said. “If we’re rolling with something, I feel like we’re supposed to keep rolling with it.”

Mazzulla experimented with a few starting groupings while Williams was sidelined, but he appears to have settled on one that has been productive, with last season’s starters Brown, Jayson Tatum, Marcus Smart, and Al Horford joined by Derrick White.

In 221 total minutes over 16 games, that five-man group has outscored opponents by 19.7 points per 100 possessions. That net rating ranks third in the NBA among the 48 lineups that have played at least 100 minutes together, trailing only the regular starting lineups of the Warriors and Nuggets.

There seems no reason to disturb such a potent pack, but last season’s regular starting unit, with Williams in place of White, was even more dominant. Over 443 minutes in 34 games, it outscored opponents by 24.6 points per 100 possessions.

That group thrived with a relentless defense that allowed just 94.2 points per 100 possessions. This season Mazzulla has constructed a more offensive-minded scheme, and the regular starters have a massive 124.4 offensive rating. To put that figure in perspective, the 2020-21 Nets’ 118.3 offensive rating is the highest in NBA history over a full season.

Regardless, everyone in the organization agrees that if the Celtics are to win their first NBA title since 2008, Williams will have to be at the center of the surge. It is just up to Mazzulla to determine how he can be most useful.

“Rob is special for us,” Brown said. “He was special for us last year, so having him confident and comfortable is going to be key as he’s starting to integrate back and get healthier and starting to gain his confidence. That’s what we need, because down the line, Rob brings an element to the game that I don’t think anybody else on our team can bring.”

Williams appeared tentative when he returned two weeks ago, but he is rounding into form quickly. He had his best game of the season so far Tuesday, tallying 11 points and 15 rebounds in just 21 minutes. During his 92 total minutes on the court, the Celtics have a plus-9.4 net rating. For the year, that trails only White and Tatum.

“You don’t want to mess up the flow of things,” Williams said. “So you’ve got to try to figure out where you fit in and help them.”

Williams has yet to play more than 22 minutes in a game, and it’s certainly possible that the idea to keep him in a backup role is rooted in a desire to preserve him for the playoffs. Or, the next time the Celtics find themselves in a rut, shaking things up by putting Williams back into the lineup could be an obvious tweak.

“We need Rob to be confident and comfortable in whatever role he’s in,” Brown said. “So I’m sure we’ll figure it out.”

Adam Himmelsbach can be reached at adam.himmelsbach@globe.com. Follow him @adamhimmelsbach.