Former five division world champion Floyd Mayweather Jr. opened up the door to a ring return this past Saturday night, when during a Showtime televised interview he admitted to be involved in discussions with Showtime/CBS for a potential comeback with a "nine-figure" payday. 

"If I came back, of course, it would have to be a nine-figure payday and probably a championship fight and a nine-figure payday," Mayweather said.

Showtime executive vice president Stephen Espinoza said he is among the minority in boxing who believe Mayweather won't come back. But Espinoza said he also believes a second fight between Mayweather and Pacquiao would do well.

"All of us here would love to see that fight again -- or any other fight with Mayweather," Espinoza said to Fox Sports.

Speculation of a Mayweather comeback was further fueled when the boxer's company recently trademarked several terms like "TBE 50" and "TMT 50" - which both point to a 50th fight. Mayweather retired last September, at 49-0, after beating Andre Berto.

Top Rank's CEO Bob Arum believes the biggest money fight for Mayweather is still a rematch with Manny Pacquiao, who himself retired last May. That fight sold 4.6 million pay-per-views and generated over half a billion in revenue.

"Obviously, he's coming back," Arum said of Mayweather. "And I can't see him making the kind of money he's talking about with anybody other than Manny."

"If they fight anybody else, there's going to be that hangover. If they fight each other, people will be attracted to the fight. It won't do what the last fight did, but it might do 50 percent of the last fight."