LAS VEGAS — Manny Pacquiao may meet an old foe in a new place in September. Promoter Bob Arum said he is trying to put together a fifth fight between Pacquiao and Juan Manuel Marquez and shopping it to casinos in Macau and Singapore. He said Saturday night at the Brandon Rios-Mike Alvarado fight that the bout would likely be at one of the Venetian hotel-casinos in Macau or Singapore. “The thing we're waiting on is which one of their hotels they want to do it at,” Arum said. Marquez would be the most likely opponent for Pacquiao, though Arum indicated earlier that Timothy Bradley — who won a disputed decision over Pacquiao last year — is another possibility. Marquez knocked Pacquiao out in the sixth round in December, flattening the Filipino fighter with a right hand that left him face down on the canvas for 2 minutes. It was the first win for Marquez in four fights between the two rivals. If Pacquiao meets Marquez, it could be held far from the Las Vegas Strip, where they fought all four of their fights. The MGM Grand hotel would ordinarily figure to be the host for the bout, but the hotel reportedly is holding a September date for Floyd Mayweather Jr., assuming he beats Robert Guerrero at the hotel May 4. Arum is in Macau this week for the fight card Saturday night at the Venetian featuring two-time Olympic gold medalist Zou Shiming of China in his pro debut. — AP