The only exception in college is if the defender was blocked into the passer. The NCAA allows each player five years to complete four years of competition. During the course of play it is not uncommon for a player to commit an illegal act. If the contact is before the ball is in the air it will be called defensive holding. Minnesota still will be playing games with postseason implications by the time Peterson might be available.
If a player enters the penalty area before the ball is in play and fouls or is fouled by an opponent, the goal kick is retaken and the offender may be cautioned or sent off depending on the offence.