College football is no pushover, but adjusting from the rigors of the college game to the NFL is one of the toughest parts of becoming a pro. At the running back position this could not be more true, and there are a handful of rushers in the 2013 class that won't withstand the beating.
This year's running back class has some huge potential, with guys like Marcus Lattimore, Eddie Lacy, Giovani Bernard and Kenjon Barner, among other players who could become regular contributors before too long.
But there's also no shortage of players who come into the league with too much baggage that don't fit the mold of a NFL running back.
Let's take a look at the rushers who won't be able to make a name for themselves in the NFL due to their physical detriments.