How well would he do? I don’t know if he’d win and he definitely wouldn’t outbox Usyk but I think he would have gave him hell.
This fight was a joke. Dude was so out of shape he really shouldn’t have been allowed to fight.
http://thaboxingvoice.com/wp-content/uploads/2015/03/MitchellWitherspoonWeighIn_Hoganphotos3.jpg
Prime Witherspoon was about 10lbs lighter & in much better shape, in the 230s, its very possible he beats Usyk or at worst loses a close decision.
He nailed Usyk with some good shots and was hanging in there before he gassed.