"Kemba was sore today," Celtics coach Brad Stevens said after Saturday's practice. "I think that he'll go through stuff in the morning tomorrow and have a better idea on him.
"Rob's doubtful. He probably won't do anything in the morning and see how he feels as we get closer to game time. But you saw him last night, even in his stint, I thought he looked pretty limited. So we're hopeful to have everybody available, but at least in Rob's case, I'd say that's probably doubtful."
Walker popped up on the injury report for the first time before Game 3. While he played 34 minutes in Friday night's 125-119 victory, one that brought the Celtics back to within 2-1 in this best-of-seven series, Walker struggled mightily, going 3-for-14 from the field and scoring just six points. He did grab eight rebounds, but also had only three assists and five turnovers.
"It wasn't really Kemba's night offensively," Jayson Tatum said after Game 3, in which he scored 50 points to carry Boston to a win. "But being out there with both groups being engaged, that won't necessarily show up in the stat book, but we wouldn't have won without him. Obviously, he's going to respond. Expect a big game out of him on Sunday."
Williams played six minutes before exiting with the sprained ankle, which occurred on the same leg that has been causing him pain from a case of turf toe for the past several weeks.
Before Game 3, Stevens said that Williams, who had nine blocks in Game 1, was Boston's "wild card" in this series, as his athleticism and size make him effective against Brooklyn's soft interior defense. Now with Williams unlikely to play, Boston will need another effort from veteran big man Tristan Thompson like the one it got in Game 3, when he had 19 points and 13 rebounds in 30 minutes. The Celtics will try to even the series in front of a packed house Sunday night, as Boston's COVID-19 restrictions were officially lifted Saturday.
"It was good, but I can't f---ing wait until Sunday," Thompson said after Game 3. "[Seventeen thousand fans], green, I'm going to see the leprechaun, I can't wait.
"That's what Boston is all about. That's what the fans are about. They are going to give us that life, that juice, that energy. They haven't seen us all in this arena in a long time, so I know everyone is excited. I can't wait. I'm super excited."
Jeff Green, meanwhile, remains out for the Nets with a plantar fascia strain in his left foot.