Floyd Mayweather Jr. and Manny Pacquiao will be fighting on March 13, but it won't be against each other.

Pacquiao will fight Joshua Clottey on March 13 at the new Cowboys Stadium. Mayweather will also fight on March 13 against an opponent to be determined Golden Boy Promotions CEO Richard Schaefer told ESPN.com.

Talks broke down between Top Rank and Golden Boy Promotions because of a disagreement over blood testing. Mayweather wanted random blood testing, while Pacquiao didn't.

The sides enlisted the help of retired judge Daniel Weinstein to mediate the situation. After numerous hours of intense negotiationing, there was no agreement, which prompted Top Rank boss Bob Arum to say "the fight's off".

advertisement | advertise on newsday

Schaefer said he hoped to have an announcement on Mayweather's opponent in the next few days.

Rumors have circulated that former 140-pound IBF champion Paulie Malignaggi will be Mayweather's next opponent. A DiBella entertainment spokesperson said last week that everything is "up in the air" regarding Malignaggi's next opponent.