San Diego Chargers running back Ryan Mathews left Sunday's game against the Carolina Panthers with an apparent shoulder injury. According to team officials, his return is questionable.

Mathews leaving the field is a scene San Diego fans have seen too often while he's been a member of the Chargers. In Sunday's game it was a routine run that he got up gingerly from. Although he left the field under his own power, it was clear the third-year running back was in a lot of pain.

Running for 22 yards on five carries, Mathews was having success against a Carolina defense that struggles against the run. Now, San Diego turn to power back Jackie Battle, who has been reliable in limited time this season. Appearing in 13 games, Battle has rushed for 223 yards and three touchdowns. This isn't an unfamiliar situation for the Chargers, and now they look to dig themselves out of a hole -- down by 21 points late in the first half.