Valero, yes, seriously. He has the footspeed advantage to cut off the ring (not that that's difficult against PBF) and the speed and work rate to get past Mayweather's defence. Valero UD.
Bad question. Floyd beats the stuffing out of Valero and possibly stops him. Particularly the current version of Valero who wants to keep his stoppage streak going. That desire to stop Floyd would see Valero getting countered to hell and back.