Manny Pacquiao will take on tough Ghanaian Joshua Clottey in March after the proposed fight with Floyd Mayweather fell through.The Filipino favourite and pound-for-pound rival Mayweather have failed to agree on terms for a proposed March 13 Las Vegas super-fight, with broken down negotiations now irretrievable.The argument stems from Mayweather's insistence on random blood and urine testing ahead of the fight, with WBO welterweight champion Pacquiao launching legal action and all parties now conceding that the fight will not materialise.Promoter Bob Arum has been arranging alternative opposition in the meantime, with former welterweight champion Clottey set to step in to fight for Pacquiao's title.It was initially suggested that new WBA light-middleweight title-holder Yuri Foreman would fill the spot but Clottey, who like Foreman is an Arum Top Rank fighter, is next in line."(Clottey's) a real strong, aggressive and hard punching African from Ghana and he poses a real test for Manny," said Arum."There's always later in the year and there's next year, it's up to Mayweather. But if he starts this nonsense again with testing or anything then let him take a walk," said Arum."We are not going to get into a debate with him ever again on stuff that we know nothing about and that only regulators really can understand."Clottey, who has a 35-3 record, went down to a narrow points loss to Miguel Cotto - the man Pacquiao beat in November - the last time he fought. Source: SkySports