Howard was removed from Saturday's start against the Marlins with right shoulder stiffness, Meghan Montemurro of The Athletic reports.
The 24-year-old exited during the fourth inning due to the injury after surrendering three runs on two hits with five strikeouts and two walks over 3.2 innings. The severity of the injury remains unclear, leaving Howard's availability for his next turn through the rotation up in the air.