During Wednesday's practice, Miami's three-point shooter Mike Miller suffered what appears to be a serious injury to his thumb on his right, shooting hand.
Miller will be examined by a hand specialist in South Florida on Thursday.
"It was just a drill," Erik Spoelstra said. "He got it caught in a jersey with some contact, on a post-up."
Even if surgery is not needed, Miller could be out as many as six to eight weeks or longer.