Celtics forward Paul Pierce said he twisted his left knee during shootaround Sunday morning and aggravated it in the second quarter of Game 4 vs. the Hawks.
"I kind of tripped over somebody's foot and turned the knee," said Pierce. "It's a little bit sore right now, so we're just going to take precautions tonight."
Celtics coach Doc Rivers said Pierce was dribbling when he injured the knee Sunday morning, and said he didn't know if he would be able to play Sunday night. Pierce played just 17 minutes but scored 24 points, hitting 10 of 13 shots from the floor. He left the arena shortly after speaking to reporters, and he did not appear to be favoring one leg as he walked out of the locker room. Neither Pierce nor Rivers could give an expectation of Pierce's availability for Game 5.