I'd have Witherspoon the clear favourite if they both showed up at their best. Superior boxer and also a big puncher. I have little doubt that Witherspoon could do what Bentt and Mercer did and stop Morrison.
I think Witherspoon takes this one. I could picture him catching Morrison at some point with his clubbing right hand and following up finishing Morrison off. The most likely scenario I feel would be the fight goes about 5-6 rounds. Morrison has a few good moments where he looks to have hurt Witherspoon with his power punches but then gets caught with a clubbing shot from Witherspoon, he wobbles or hits the deck and Witherspoon follows up clubbing away on Morrison who tries to survive but clearly has no legs and the ref eventually elects to stop the fight after Morrison is clearly rendered helpless.
Tim and confident.Better boxer ,better fighter ,more durable,better stamina,similar power. Don't see any area of this match up where Morrison looks favourable.
Witherspoon with ease. The only hope Morrison would have had is an early knockout in the manner of a Bonecrusher Smith. Witherspoon was one of the most underrated champions and would have given Tyson a run for his money in the 80's given the right support. Unfortunately for him Don King got his greedy mitts on him and undoubtedly influenced the course of his career in a negative way.