The San Francisco 49ers suffered another injury to a running back on Sunday when LaMichael James sustained a dislocated elbow during practice, CSNBayArea.com reported.

James will be sidelined about a month, according to the report.

James, who is entering his third NFL season, was the 49ers' top punt returner last season and carried the ball just 12 times for 59 yards in 2013. However, he was expected to get more playing time on offense after Kendall Hunter suffered a season-ending ACL injury on Friday.

James was injured during a routine blitz pickup drill, and his absence depletes the depth behind starter Frank Gore. Gore, Carlos Hyde and Jewel Hampton are the 49ers' only healthy running backs. Marcus Lattimore remains on the non-football injury list as he continues to rehabilitate from a knee injury he sustained in 2012.