Hard to tell, we got a glimpse of what McClellan could've been but his career was cut fairly short, canelo is a great counter puncher with a great defence and chin, very unlike gerald's other opponents, but canelo also never fought anyone as explosive or powerful as McClellan either. Either canelo by u.d. or gerald takes his head off. Geralds key to winning this is landing bombs on canelos liver then going up top when his body couldnt take anymore. Canelo could win this by slipping and countering geralds right hand which he often liked to lead with and trying to follow it up with his own hooks to the body.
Canelo is a far better fighter than G-man was, against their best opponents Canelo looked better, GGG is far better than Jackson and Benn were and while G-man looked far better v Jackson than he did v Benn he still didn`t display any deensive skill, Canelo outpoints him easily.
Probably Canelo. McClellan was an absolute beast, but Canelo has a fantastic chin and much more experience in long, competitive fights. McClellan does have significant physical advantages though. Either G-Man gets him out of there early, or Canelo rides some rocky moments, takes over and outpoints him close (with one judge scoring it a shutout) or stops him late. Probably the latter. As someone said above, the key for McClellan would be attacking the body.
At his best? G Man destroys Canelo. I have no doubts Everybody making a big deal about Canelos win over GGG but keep forgetting that GGG was past his prime and Canelo STILL managed just to squeak by. Canelo signs to fight and older Mayweather and gets ScHOOLED the entire fight. Canelo has never given me a performance where i was wowed. G MAN was a BEAST. And Canelo has never faced that ever.