The Mayweather's are underestimating Pacquaio's punching power

I agree. I think Floyd knows Pac can punch, hence why he's taking this serious and avoided it for so long.

I also think Floyd is a very underestimated puncher, all his sparring partners and opponents say so. I think if Floyd loads up, he can definitely knock Pac down and if he times him just right, possibly even a KO.

 

Pacquiao circa '09 had the power to stop Floyd if he caught him enough, that power and speed has since waned.

In any case Floyd will not be underestimating Manny, he is the most diligent trainer in boxing and is naturally cautious.