Manny Pacquiao's promoters say his prospective bout with Floyd Mayweather Jr. is off after mediation failed to resolve differences over drug testing, scrapping what was likely to have been the richest fight in boxing history. The bout was slated for March 13 at the MGM Grand Garden in Las Vegas, but Top Rank said it couldn't reach an agreement with Golden Boy Promotions, which represented Mayweather in the negotiations, after nine hours of mediation Tuesday and more discussions Wednesday. Although neither side was allowed to publicly discuss the specifics of their dispute, Mayweather apparently balked at a compromise over the stringent drug-testing requirements his camp insisted upon. “I knew this was going to happen,” said a weary Bob Arum, Pacquiao's promoter. “You had to play it out.” Golden Boy chief executive Richard Schaefer and Mayweather adviser Leonard Ellerbe didn't immediately return phone messages. The promoters went into the lengthy mediation Tuesday. Both sides claimed every other detail for the fight had been decided, but Mayweather had demanded random blood testing in addition to unlimited urine testing, with Pacquiao unwilling. The fighters' representatives apparently thought they had a compromise after the mediation. The promoters were widely expected to formally announce the bout Wednesday – but subsequent discussions with Mayweather during the day led Top Rank to declare the fight canceled. Arum was left fuming by Mayweather, who fought under Top Rank promotion for several years. “I've been saying this for years: He's a psychological coward who doesn't want to fight anybody who has a chance of beating him,” Arum said. “He walked away from a rematch with Oscar (De La Hoya) that would have paid him a fortune because De La Hoya held him close in the first fight (in May 2007).”
