Montario Hardesty strained his right calf in Sunday's 20-10 loss to the San Francisco 49ers, leaving the Cleveland Browns dangerously thin at running back.
Hardesty didn't return after injuring the calf while running a passing route during the first half, and will undergo an MRI exam on Monday. He said the injury didn't appear serious, though, and was walking around the Browns locker room after the game.
The Browns were already playing without injured starter Peyton Hillis, who missed his second straight game with a strained left hamstring.
With Hillis and Hardesty sidelined, the Browns turned to Chris Ogbonnaya, who was just signed two weeks ago. Ogbonnaya didn't have much of an impact either, rushing for 37 yards on 11 carries.
Brandon Jackson and fullback Owen Marecic are the only other backs on the Browns' roster.
The Associated Press contributed to this report