Mayweather doesn't really want to face Pacquiao (coming from a PBF fan). PAC is a stylistic nightmare for Floyd. The fact he's a southpaw creates a lot of problems for Floyd. I believe Mayweather is a superior fighter but he's just gonna have problems with a fast southpaw. What does he do?

He goes and dominates the guy that almost beat Pacquiao but is taylor made for his style. Marquez is orthodox and slower than him: perfect. By destroying JMM (a guy that gave PAC fits), he will make a strong statement without having to take the risk against Manny. I might be wrong but I think this is what he's thinking. If I'm correct he'll probably stop Marquez. While in most fights he's lazy, I doubt he will this time.