By Rick Reeno

WBC/WBA welterweight champion Floyd Mayweather J.r (48-0, 26KOs), 38-years-old, is still expected to fight on September 12th at the MGM Grand in Las Vegas.

The current frontrunner is former welterweight champion Andre Berto, but a deal has not been finalized.

There is still no clear decision on whether or not the fight will end up on CBS, but there is very little time to property market a major pay-per-view event. 

Regardless of the opponent or the details, Mayweather's next fight will be his final obligation of an exclusive six-fight contract with Showtime/CBS. Mayweather signed the deal in early 2013.

Sources with knowledge of the details have advised BoxingScene.com that CBS is negotiating a three fight extension - and that may be a big reason as to why the announcement of his upcoming fight is taking more time than usual to announce.

Mayweather's current per fight guarantee is reportedly in the neighborhood of $30 million.

While Mayweather is claiming that his upcoming return will be the "final fight" of his pro career, many insiders in the industry believe he will fight again in 2016. CBS is attempting to finalize a deal which guarantees them the rights to Mayweather's next three fights - in the event Mayweather makes a decision to continue his career.

An extension of Mayweather's current agreement is almost sure to include an increase on his guarantee, and also prevents Mayweather from holding his 50th fight with network rival HBO.