Johnson was removed from Wednesday's minor-league game after being hit in the leg by a comebacker, Alex Speier of The Boston Globe reports.
Johnson hadn't allowed a hit before exiting the game after being pegged by a liner in the first inning. This is a tough break for Johnson, as the southpaw just recently rejoined Triple-A Pawtucket's rotation after being shut down with shoulder fatigue. The severity of his injury isn't known at this point, but expect an update following the conclusion of Wednesday's contest.