The Manny Pacquiao vs Floyd Mayweather welterweight title clash scheduled for March 13 may not happen because of Pacquiao’s camp’s refusal to agree to the Olympic-style drug testing procedures that the Mayweather camp is insisting.

Mayweather requested that the drug testing for the fight be in compliance with the United States Anti-Doping Agency, which handles testing for Olympians, “to ensure fair play and sportsmanship by both fighters.”

Top Rank promoter Bob Arum accused Mayweather’s camp of raising the issue not because they were worried about Pacquiao taking performance-enhancing drugs, but because Mayweather never really wanted to fight Pacquiao in the first place.

“We’re going in a different direction,” Arum told the Grand Rapids newspaper. “What I believe is that Floyd never really wanted the fight and this is just harassment of Pacquiao.

“We appeased Mayweather by agreeing to a urine analysis at any time, and blood testing before the press conference and after the fight. Mayweather pressed for blood testing even up to the weigh-in. He knew that Manny gets freaked out when his blood gets taken, and feels that it weakens him. This is just harassment and, to me, just signaled that he didn’t want the fight.”

Golden Boy Promotion’s CEO Richard Schaefer, who is negotiating the fight with Todd duBoef, Top Rank’s president, said that the Filipino fighter refuses to have his blood drawn within 30 days of the bout based on his superstition of testing so close to a fight.

“Todd told me that Pacquiao has difficulty with taking blood and doesn’t want to do it so close to the fight,” Schaefer said. “He, Pacquiao, would only agree to have blood drawn before the kick-off press conference and after the fight.”

Mayweather Jr. said Pacman should explain himself because of his reluctance to be tested.

“I understand Pacquiao not liking having his blood taken because, frankly, I don’t know anyone who really does,” Mayweather said in a statement. “But in a fight of this magnitude, I think it is our responsibility to subject ourselves to sportsmanship at the highest level. I have already agreed to the testing and it is a shame that he is not willing to do the same. It leaves me with great doubt as to the level of fairness I would be facing in the ring that night.

Watch: Pacquiao-Mayweather Fight Off

If the Pacquiao-Mayweather fight never happens, it will be a major disappointment to all the boxing fans and to “boxing “itself. The clash between the two pound-for-pound kings may now, well, be the greatest fight that never was.