88 was forced into a RB position when Lacy and all others went out. Before that, MM was using Cobb out of the backfield to force mismatches, but from my recollection, Cobb never posed much of a threat as a runner so teams didn't adjust as MM would have liked. 88 was not a bad runner and seemed to have potential but the bulk he eventually added seemed to slow him down a bit. I always though 88 never reached his potential under MM and might have been more successful under a different coach, but it seems he hasn't done anything post-Packer so maybe the Packers got all he had out of him.