Los Angeles coach Byron Scott says he doesn't know much more other than that the 37-year-old Bryant told Scott that his shoulder hurts.
Bryant dunked for the first time this season on Friday against the Houston Rockets, but Scott says there's no way of knowing if that's when an injury occurred.
It will be the fourth game Bryant has missed this season, which he has said will be his last. He leads the Lakers in scoring at 16.7 points per game.
Scott says Anthony Brown, who has appeared in only five games all season, will replace Bryant in the Lakers' lineup.