The return of Robert Williams is "pretty close"

BOSTON -- Time is running out for the rest of the NBA to take advantage of a Celtics team that isn't at full strength. Center Robert Williams is "pretty close" to returning, which will only make the Celtics even more of a force on the floor.

Ahead of Sunday night's win over the Brooklyn Nets, Boston head coach Joe Mazzulla shared another positive update on Williams, who underwent arthroscopic knee surgery in late September. Williams has been ramping up his on-court activity in recent weeks, and now it's just a matter of conditioning before he returns to NBA action.

"He went through another session today. He's progressing really well," Mazzulla said of Boston's game-changing center. "Pretty close to returning, along with the timeline. It's just a matter of getting him back conditioning-wise and making sure he's comfortable and ready to go."

Williams underwent surgery on his left knee 10 weeks ago, and was given an 8-12 week window to return. It's been reported that he could be back for Boston's Christmas Day tilt against the Milwaukee Bucks at TD Garden.

Williams started participating in scrimmages last week, and his activity will only ramp up with his return getting closer.

"We just want to make sure that he's in the right place when he comes back," added Mazzulla. "So, he's doing a great job. Doing the best he can."

The Celtics haven't really missed Williams to this point, though their defense has left a lot to be desired. Still, Boston improved to an NBA-best 19-5 on the season with a 103-92 win in Brooklyn on Sunday night, which was the team's best defensive game of the season.

The C's defense will only get stronger when Williams and his shot-blocking prowess returns to the mix.