Avery Bradley is out with a sports hernia.
Bradley missed Thursday's game at Golden State and is also expected to miss Friday's game.
"We are concerned," Doc Rivers said. "We've got to go through the right stuff and make sure he's in a good place with his health. I think we're going to send him to a doctor and let him check and see."
Bradley has dealt with groin issues throughout the season, which is his last before free agency.