Beal scored 12 points before taking a nasty fall on a layup attempt with 6:17 remaining in the period. He did not return.
Wizards coach Randy Wittman didn't update Beal's condition after the game.
Beal missed 16 games in December and January with a right leg stress reaction. He entered Saturday averaging 18.0 points in 40 games.
The Associated Press contributed to this report.