berto looked like a beast. im sure floyd was worried. "fug hes on the shi- again" https://usatboxingjunkie.files.wordpress.com/2015/08/c02-v2-boxing-0807.jpg?w=1000&h=745
Well...he IS bigger than Floyd. He'll probably get in the ring close to 160. He's always been a bigger guy than Floyd
He'd have to put on more muscle and be thicker in the body to make the weight since Floyd is taller and has longer arms. Mayweather has only ever fought like five guys who were naturally bigger than him measurement wise: Corrales, Alvarez, De La Hoya, Mosley, Ortiz. Most of the people he fights were light welters who moved up for a payday.
It shouldn't matter. Floyd's been smaller than a quite a few opponents. He's a much better boxer than Berto and that will be the difference.