San Francisco 49ers reserve LaMichael James injured his left knee during Thursday night's preseason victory over the San Diego Chargers.
The Sacramento Bee reported Friday that James, the team's main punt returner and backup running back, sprained the medial collateral ligament in his left knee.
The severity of the injury was not immediately known, but the team will go to Kyle Williams to return punts and Quinton Patton will return kickoffs for the time being.
James is behind Frank Gore and Kendall Hunter on the depth chart at running back.
James had only 55 rushing yards on 24 carries during the preseason.