Lamb's return is doubtful, according to the team.
Lamb appeared to step on someone's foot along the baseline and came up limping. He played four minutes and did not have any points.
The Hornets are hoping to get through the preseason without any more injuries. They've already lost starting small forward Michael Kidd-Gilchrist for six months to a shoulder injury.
Earlier in the game, Charlotte had a scare when point guard Kemba Walker tumbled to the court after a drive to the basket. He remained on the floor for several minutes, was taken to the locker room but was diagnosed with left heel contusion. He did return to the game.