By Rick Reeno

Golden Boy Promotions CEO Richard Schaefer confirmed to BoxingScene.com that WBC 154-pound champion Saul "Canelo" Alvarez (41-0-1, 30KOs) will no longer be a part of the Floyd Mayweather vs. Robert Guerrero undercard, which is scheduled to take place on May 4th at the MGM Grand in Las Vegas.

There were deep negotiations for Canelo to face WBA champion Austin Trout (26-0, 14KOs) on the card, as the Showtime Pay-Per-View co-feature.

For several weeks, Schaefer has been working very hard behind the scenes to make that doubleheader possible, but the agreement hit a major snag in the last few days.

As BoxingScene reported earlier, Canelo was refusing to fight on the Mayweather-Guerrero undercard - unless Mayweather contractually agreed to fight him on September 14th.

"[If] Floyd does not sign our agreement for September, we are not going to fight on the evening of May 4th, and then we will determine if we'll fight on April 20th or the week that follows the May 4th date," Canelo stated.

Mayweather rejected Canelo's demand and he did have a strong position. He refuses to look past his upcoming fight with Guerrero by already signing to face another opponent in September.

At the moment, negotiations are ongoing to finalize Canelo-Trout for a Showtime televised date of April 20th, potentially in San Antonio, Texas. If Canelo and Mayweather win their upcoming fights, then Schaefer will explore the possibility of the two of them fighting each other later in the year.

However, moving an event is no longer an easy maneuver for Schaefer. In order to move Canelo-Trout to April 20, Schaefer and Showtime were forced to move the anticipated featherweight fight between Abner Mares and Daniel Ponce De Leon. While it was initially being circulated that Mares-Ponce De Leon would land on May 18th, both Golden Boy and Showtime officials have told BoxingScene that is not the case, at least for the moment. Schaefer was looking to stage a big doubleheader on May 18th, with Lucas Matthysse facing Lamont Peterson and Devon Alexander taking on Kell Brook, but right now everything is up in the air.

"[Canelo] basically was willing to be on the [Mayweather-Guerrero] undercard if he had a signed deal in place to face Floyd Mayweather [and] that didn't happen. Floyd feels, and correctly, that this is a big fight, a dangerous fight with Robert Guerrero. He's not looking past that. We're just going to see what happens. If Canelo wins, and then Mayweather wins - we'll take it from there," Schaefer told BoxingScene.com.