This makes me smile. He will get destroyed. He's a great boxer, but thats only one element of fighting. He has no ground skills and no kicking skills. How is he going to stop a wrestler from slamming him on the mat? Once on the mat, he has to worry about chokes, armbars, leglocks etc.

He will have to train for about 2 solid yrs. on his ground game. He will have to adjust his striking game. In boxing, if there's a clinch; the ref breaks it up. Now he will have to worry about getting kneed in the ribs.

I hope he does make the transition. I want to see BJ Penn choke him out.