But three months later, another expert has risen to poke the fire and prepare fans for a rematch.
A fresh crop of videos of the 50-0 immortal working out posted to his Instagram has iconic US sportscaster Jim Lampley suspicious with the 68-year-old pulling out a bombshell accusation.
"Why else is he putting out videos of him working out?" Lampley told TMZ. "He allowed Conor McGregor to 'win' three rounds. Why did the whole thing last 10 rounds, etc.? It's all a setup."
Lampley said Mayweather could easily make another $150 million from a rematch with the UFC lightweight champion, claiming "suckers" would be drawn to the spectacle.
"Why should he retire?" Lampley said. "He created a marvellous scam with this whole thing. He allowed Conor to quote 'win' three rounds, so the whole global MMA wish community could have something to latch onto.
"I think there's a decent chance, there's enough suckers out there, Floyd could maybe make another $150 million."
When asked if he thought Mayweather would be stupid enough to risk his legendary undefeated record for another shot at McGregor, Lampley replied in incredulity.
"Risk?" Lampley said. "Risk? Did you just associate the word risk with Floyd Mayweather? This is not about risk, young man. Risk has nothing to do with it. There's no risk involved for him.
"So we're betting on the question, does Floyd want to make another $150 million? Why would that even be a bet?"