Former three division world champion and soon to be Hall of Famer, Shane Mosley, has serious doubts that his former foe, Floyd Mayweather, will return to the ring in 2020.

Last month, the former five division world champion took to social media to announce that he's coming out of retirement in 2020.

Mayweather retired from the sport back in 2017, after stopping UFC superstar Conor McGregor in a mega-bout that generated over 4 million buys on pay-per-view.

Mayweather, 42-years-old, appeared in the ring on New Year's Eve of December 2018, when he traveled to Japan to take part in an exhibition bout where he demolished Japanese kickboxer Tenshin Nasukawa in a round.

A few weeks ago, former five division world champion courtside at an NBA game with UFC President White, and claimed that something big was coming in 2020.

According to White, he wants to get Mayweather in the ring in October or November. But there is no word if the "fight" will be an exhibition or a sanctioned contest.

Mayweather has not taken part in a boxing match, with an actual boxer, since his September 2015 twelve round decision win over Andre Berto. Mayweather will turn 43 in February.

Mosley does not see Mayweather, at his age and lack of activity against top fighters, to risk his 50-0 record against anyone of note.

He slightly sees the scenario of Mayweather doing a rematch with WBA welterweight champion Manny Pacquiao. But even that looks unlikely when considering Pacquiao's activity level against top competition in recent years.

“It would be interesting but I don’t think he’s gonna come back. He doesn’t want to lose the 50-0 record. Why would he come back? For what reason?," Mosley told IFL TV.

“Manny Pacquiao’s been in there with world [class] fighters, Floyd Mayweather’s been in there with UFC guys and kick boxers. It’s a whole different thing. For him to get back in there with Manny Pacquaio, I think that’s what they’re talking about, I don’t see that. But you never know, it could happen.”