NFC Divisional Game: Green Bay Packers at San Francisco 49ers

File - In this Aug. 10, 2012 file photo, San Francisco 49ers running back Rock Cartwright (28) runs against Minnesota Vikings linebacker Tyrone McKenzie (58) and defensive end D'Aundre Reed (91) during the first half of an NFL preseason football game in San Francisco. To this day, the special teams standout and reserve running back keeps his mother Johnetta Cartwright close each time he steps onto the football field _ and that hasn't changed as he changes teams for the third time in his 11-year NFL career. He's getting his chance with the reigning NFC West champion San Francisco 49ers. (AP Photo/Paul Sakuma, file)