I've heard this already with most of his other opponents. 
Once again, Floyd is brilliant BOXER. You can't hit what you can't catch. This would be no different.
GGG too big, no biggie if he didn't fight him.
Silver medalist Olympian, he has boxing pedigree. GGG would apply intelligent pressure and break Mayweather down. Mayweather wouldn't be able to pot shot and win like he usually does. That shotgun jab of GGG would rock him just alone.
I never pick against Mayweather but this fight I would.
But it would never happen...