Mitchell (hamstring) wasn't listed on the 49ers' injury report Wednesday, Eric Branch of the San Francisco Chronicle reports.
The 49ers kept Mitchell on the sideline during the preseason due to a hamstring concern, but he now has more than a week of on-field work behind him and was without limitations in the first official practice ahead of the season opener. With his health not in question, the second-year back can assume leadership of the team's backfield, which equated to 94.7 yards from scrimmage per game and seven total touchdowns in 14 appearances (including playoffs) a season ago.