Personally, i am unsure if diaz can prepare cotto gameplan/intellectual wise properly for mayweather, but on the same token, i think he would get cotto ready physically.
Steward on the other hand, i think could prepare cotto gameplan wise properly, with a little less physical wise.
(i could be wrong on both accounts, just wondering what your thoughts are)
It'll be Diaz.
I met him at the airport as he was flying out of Puerto Rico with Cotto's legal advisor just last week. I prefer "Mr. Sports Science" himself, he has the perfect combination of boxing and ultimate conditioning knowledge.
The guy thats training him now did a good job so far he looked fresh and young in the ring of course it was agains't Margarito but still he looked good doing it.
I think Diaz would be better in both aspects.
I think it would be easy for diaz to overlook mayweathers greatness and give cotto faulty advice. He could also give great advice, idunno.
Personally, im happy with either trainer, im just wondering if diaz can properly gameplan against mayweather.
I say to stick with what you have. He seemed to gel nicely and maybe Diaz can bring different things to the table that maybe Mayweather hasn't either seen before or hasn't seen in awhile.
We all know how Steward fighters fight and what they'll bring to the table. Hell, I know what Steward will tell him to do. Throw the jabs, get in close, keep his chin on Mayweather's chest and hit the body. What happens when that stops working and Floyd will adjust and make Cotto move and box? What more will Steward bring to the table that Floyd isn't prepared for.
I see no positives in regard to replacing Diaz w/ Steward at this point. At least he isn't a junior like Santiago was and will ensure that Cotto is updated on how he's doing in the corner and how to adjust. Live and die with the team that prepared you for your boogeyman.