Robert Williams left Sunday's game late in the third quarter due to a sprained left knee. Williams was ruled out for the rest of the game shortly thereafter.

Postgame, Ime Udoka said the Boston Celtics didn't know the extent of Williams' injury, but that the young big man was in "quite a bit of pain". Williams was ruled out of the Celtics back-to-back in Toronto on Monday and will have testing done on the injury.

In his first season as Boston's starting center, Williams has had a breakout year. He's averaged 10 points, 9.6 rebounds and 2.2 blocks per game. Williams' 73.6% shooting would lead the NBA if he qualified.