I knew that dirty flip would punk out. If he ain't on roids he should have no problem with any kind of testing that Mayweather is agreeing to take as well.
The point is to not be pushed around by Mayweather. Who is Mayweather to come in and dictate the rules when he has followed the established drug testing for every other fight in his career?
Mayweather did this to cast doubt on Pacquiao so people like you would start saying "If he ain't on roids he should ahve no problem with any kind of testing..." and "what is he trying to hide?". Then when the fight gets called off, Mayweather and his camp can say they wanted the fight with Pacquiao but Pacquiao wouldn't do the drug testing. In Mayweather's mind, he comes out of this looking like the good guy.
Over the course of his career (going on 15 years), Manny Pacquiao has gone from flyweight (maybe even super flyweight, I don't know what he fought as way back in the beginning in the Phillipines) to welterweight and won belts in 7 weight classes. Over the course of his career (going on 14 years), Floyd Mayweather Jr. has gone from super featherweight to welterweight and won belts in 6 weight classes. The Mayweather camp's accusations have always been based on the fact that Pacquiao has been so dominant moving through all these different weight classes, but Mayweather has done the same thing! Pacquiao's camp could just as easily turn this around and make the same accusations, but they'd rather fight than just stand around talking.
You people that are arguing in defense of Mayweather need to take a step back and realize that this whole situation was created by his camp to get him out of a fight that him and his camp realize he could very possibly lose without looking like they're ducking the fight. Mayweather has been ducking Shane Mosley for years too, so none of this is any big surprise to me.
Interview with Mosley from last year before Floyd's fight with JMM:
The guy has every excuse in the book. He should just retire again and disappear. He won't be remembered for anything great anyhow, that's why no one talked about him the first time he retired. The only thing he's good at is making smaller guys come up to fight him (who obviously take the fight because it gives them money and attention they've never had before in their career) and then beating them and bragging about being undefeated afterwards.