The redshirt sophomore running back already has missed one season as the result of a serious knee injury and had to sit out two games in 2012.It purely conjecture but given four full healthy seasons, the 5foot10, 210pounder could have left as the best running back in ACC history. State, he still rushed for 1,228 yards this season.Hampered by a twisted ankle in the game against the Wolfpack, Bernard put himself in the lineup for a lategame punt return and went 74 yards for one of the most memorable touchdowns in Kenan Stadium history.But running backs often pay an expensive price for their yardage in college. With 12game regularseason schedules, league championship games and postseason bowls, college players can be on the field almost as much as NFLers.And although Bernard made dozens of defenders miss, it rare that running backs don take at least one direct hit from bigger, stronger linemen and linebackers on each carry.League commissioners and officials benefit from the nonprofit