I think Mayweather dosen't need a tune up fight,he is just 31,and there is just 1 year since he last fought so he can loose the rust in the training camp and with good sparring partners.
I agree he doesnt need a tune up but I think he should just in case. Plus another W doesnt hurt for his resume if its against someone with at least soem quality before a mega fight with Pacman.
Mayweather still works out regularly he dont need a tuneup guys need tuneups when they have been sitting on there ass and doing nothing at all for over a year Floyd takes good care of himself.