The injury, according to head coach Doc Rivers, didn't appear serious. But it was enough to force him out of the final moments of practice.
"It's starting to feel better, I hope he's fine," Rivers said following the session. Pierce was spotted at the end of practice with ice on his right knee - the same one that forced Pierce to the sidelines for five games around the holidays with an infection.
"He got kneed [in] same exact spot," Rivers said. "It's just amazing the luck right now with things like that."
Video of practice with Pierce going off and Doc's commentary after the jump. Hat tip to Red's Army for finding the video.