Five division world champion Floyd Mayweather Jr. (49-0, 26 KOs), 40 years old, has no desire to fight beyond his upcoming return - and says there is no possible financial offer that will bring him back to the ring in the future.
Mayweather retired in September 2015 after winning a twelve round unanimous decision over Andre Berto.
He will officially come out of retirement on August 26th, two years later when he faces UFC superstar Conor McGregor at the T-Mobile Arena in Las Vegas.
Three weeks later on September 16th, at the same Las Vegas venue, Saul "Canelo" Alvarez will challenge IBF, IBO, WBA, WBC middleweight champion Gennady Golovkin on HBO Pay-Per-View.
Mayweather's bout with McGregor, who has no pro boxing experience, is viewed by most as a mismatch. Mayweather is expected to make over $100 million in the contest.
Should Mayweather win, a natural opponent would be the winner of the Canelo-Golovkin showdown - and he can certainly generate another $100 million payday if he decides to stick around.
Mayweather dominated Canelo back in 2013, but the Mexican superstar has greatly improved since then and racked up a solid win streak, and more importantly he's the biggest pay-per-view attraction in the United States.
Mayweather says there is no interest in fighting the winner of Canelo-GGG and he doesn't care what kind of money is presented to him.
"The first time [I retired it] was a vacation. I just needed a vacation. I just needed some time off to get my head right. The second time [in 2015] I had no plans to come back at all. And they gave me a deal that I couldn't refuse [to face McGregor]," Mayweather told Stephen A. Smith.
"I don't think [there will be another offer that I can't refuse]. Don't even go to Canelo and Triple G - it don't matter [what they offer]. I gave [my manager] Al Haymon my word. I shook his hand and gave him my word that this is the last one. That's what I wanted to do. We talked, I got much respect for him and he cares about my health. He cares about my health, he cares about me period."