Stewart (undisclosed) exited to the locker room in the first quarter of Monday's preseason game against the Hawks, Damichael Cole of The Memphis Commercial Appeal reports.
Stewart appeared to come down on an opposing player's foot and took a hard fall before limping to the locker room. If he's unable to check back in, Olivier-Maxence Prosper and Taylor Hendricks could see increased playing time the rest of the way.