HOUSTON (AP) _ Dallas forward Keith Van Horn left the Mavericks' playoff game against Houston on Thursday night with a sprained left ankle.

Van Horn was undergoing X-rays and his return was doubtful.

After coming down with a rebound in the second quarter, Van Horn got tangled up with Rockets center Dikembe Mutombo. The Dallas player landed awkwardly then rolled around on the court in agony, clutching his ankle.

Van Horn was taken to the locker room by two teammates, unable to put any pressure on the leg. He had four points, all on free throws, when he left the game.