By Rick Reeno

Multiple sources in Mexico, and the United States, have advised BoxingScene.com that WBC lightweight champion Humberto Soto is informing those close to him that he's not going forward with the May 7th rematch with Urbano Antillon, which is scheduled for the Manny Pacquiao-Shane Mosley undercard at the MGM Grand in Las Vegas.

According to sources in Mexico, Soto is having promotional issues with Fernando Beltran of Zanfer. Apparently, Soto has not signed a contract for the Antillon rematch - and there are sources who are telling me that Soto believes his contract with Top Rank/Zanfer has expired and he plans to explore his options elsewhere, which includes a possible jump to Golden Boy Promotions.  

If the situation with Soto is not resolved, don't be surprised if Antillon is reshuffled to a showdown with WBA champion Brandon Rios on July 9.