By Rick Reeno

Rising welterweight contender Errol Spence (17-0, 14KOs) has no problem with his mentor, Floyd Mayweather Jr., taking on Andre Berto or Karim Mayfield on September 12th at the MGM Grand in Las Vegas.

Most media members were in disbelief when Mayweather continuously named Berto and Mayfield as the leading candidates for his next pay-per-view outing - which Mayweather claims will be the final fight of his pro career.

Berto and Mayfield would be massive underdogs. Berto is now on a two-win streak, but lost three of his last six. Mayfield (19-2-1, 11KOs) has yet to fight in 2015 and went 1-2 last year with decision losses to junior welterweights Thomas Dulorme and Emmanuel Taylor.

Because of his busy schedule of opponents in the last few years (which included Miguel Cotto, Saul Alvarez, Marcos Maidana, Robert Guerrero and Manny Pacquiao), Spence believes the 38-year-old WBC/WBA/WBO welterweight champion has earned the right take a step down in competition for the final fight of his pro career.

"Floyd said he's going to fight Andre Berto of Mayfield, so he probably will. Floyd's probably last ten fights, or even the last fifteen fights - they were all tough fighters, tough top competition. He does deserve to step down a little bit in competition," Spence told BoxingScene.com.

Mayweather's "final fight" will be the selling point of the next pay-per-view, which is why Spence is confident that people will spend their money - regardless of the opponent involved.

"I think so [that people will watch regardless of the opponent], it's his last fight. He's a Hall of Famer. I think a lot of people will buy it just to see him fight one more time," Spence said.

Most insiders in the industry expect Mayweather, provided he's successful in September, to fight at least one more time in May of 2016. The next fight will be Mayweather's final contractual obligation to Showtime.

If Mayweather decides to go for fight number 50, as a free agent, it could start a serious bidding war between HBO and Showtime - depending on the opponent being pursued and HBO's willingness to work with Mayweather's adviser, Al Haymon, who hasn't worked with the network since they parted ways in early 2013.