im afraid not, G MAN was one hell of a puncher and a great fighter. He would have to fight Calzaghe at SMW which he was not natural weight class and JC is quite big for his weigh.

He doesnt have the same ring craft/skill as JC and he would prob try to go to war with him, which i just cant see being a good idea. If they would of fought prime, i would have JC late TKO. If they would of fought at how JC hands are now i would say Calzaghe UD.