49ers running back LaMichael James was carted off the field during Sunday's practice after sustaining an apparent left arm injury in a pass-blocking drill, the Bay Area News Group reports.

Along with rookie running back Carlos Hyde, James could see an increased role as the backup running back after Kendall Hunter went down with a torn ACL. James carried the ball just 12 times in 2013.

The 49ers will open their preseason Aug. 7 at Baltimore.

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