From what I gather this is Mayweather's side who is requesting such test to be administered and not the boxing authority or commission. Blood tests for illegal drugs and banned substances are not required by the Nevada State Athletic Commission, which would have regulatory control of the bout if it is held in Las Vegas.
Seems to me that it is either a strategy to promote the fight on an even greater level (like it would need it) or Mayweather really doesn't want to fight Pacquiao. Having never been questioned about his misuse of substances of any kind and passed all previous drug test prior to and after his fights Manny doesn't deserve to be subject to this. I don't think. You tell me. Whats your take on this issues. Promotion tactic or is Manny dirty from substances?
