Floyd Mayweather may or may not fight again although a sparring partner is convinced something is brewing. In the eyes of the boxing world, his clash with Andre Berto in 2015 remains the last official boxing match he had in his career.

But of course, some credited UFC fighter Conor McGregor for lasting 10 rounds in the ring with the undefeated American boxer. It was counted as his 50th win but not everyone felt it was worth considering.

Regardless, Mayweather has been trying to keep himself in shape. Denis Douglin shared how he was called up by the 43-year-old boxer for a sparring session at an odd time. He shared with Vegas Insider how he was called up by Mayweather at 1:00 a.m. to spar.

Like any fighter, Douglin was not about to pass up the opportunity even if it came during the wee hours of the morning. He narrated how Mayweather seemed all pumped up and promised to give him a beating. After three rounds, the Flamboyant One told him that they would box until Douglin was ready to quit.

Douglin claimed he never quit and that the two of them kept on exchanging blows for about 30 minutes. From that session, the 32-year-old fighter who has 22 wins and seven defeats across his name said that Mayweather was pretty sharp, strong and well-conditioned.

"I think he could still hang with the top guys. There's no reason to try because he's already proven himself, but if he wanted to, he could still do it," Douglin said.

The last time Mayweather was in the ring was against Tenshin Nasukawa in an exhibition boxing match. Mayweather had an easy time against the Japanese kickboxer, ending the fight in two rounds.

Looking ahead, UFC president Dana White said that he has been conversing with Mayweather and something could be coming. Most are speculating a rematch with McGregor but White reminded everyone that the Irishman is retired.

Of course, McGregor could easily unretire and face the American boxer if he wanted to. Most believe that it all boils down to the money on the table - perhaps the only thing that can entice Mayweather to fight again.

But as far as real boxers in the ring, the plausible choice remains Manny Pacquiao. There have been teasers of that happening but nothing has gone beyond that. With both Mayweather and Pacquiao reaching a peak age, the chances of seeing these two future boxing Hall of Famers is fading.