Floyd Mayweather’s unanimous decision victory over Andre Berto on Saturday night didn’t feel like the last fight in the career of one of the all-time greats. The undefeated boxer took on a heavy underdog in a bout that didn’t receive much attention outside of the boxing world. But Mayweather insists that his career in the ring is now over.

“You’ve got to know when it’s time to hang it up, and it’s my time to hang up,” Mayweather said. “I’ve been in the sport 19 years and been a world champion for 18. I have nothing else to prove in the sport of boxing.”

Mayweather improved his record to 49-0, matching Rocky Marciano’s iconic mark. Fans were disappointed in his choice to fight Berto, against whom Mayweather was given 30/1 odds just hours before the fight. But no matter what welterweight Mayweather could have fought, he would have been a heavy favorite.

Even though Mayweather has said for a while that his career would end with his six-fight Showtime contract, many that cover the sport find it hard to believe that Mayweather won’t at least try to get a nice and even 50th win to surpass Marciano.

Mayweather will turn 39 in February, certainly not a young age for a boxer. His skills might not be where they were when he was at his peak, but Mayweather clearly remains the best boxer in the world. His ability to avoid major punishment in the ring has kept him near the top of his game, and he could stay there for a few more years.

The Michigan native doesn’t need the money after earning more than anyone in the history of the sport, but Mayweather still has the opportunity to make hundreds of millions of dollars in the ring. Manny Pacquiao is seeking a rematch with Mayweather, and another fight between the two boxers would result in a monster pay day. Pacquiao's trainer Freddie Roach told International Business Times in August that Pacquiao's injured shoulder is feeling better and that he expects him back by December at the earliest. Roach also said that Pacquiao may need to fight another opponent before he steps into the ring with Mayweather again.

The May 2 mega-fight between the sport’s top two pound-for-pound stars shattered several records, generating the most pay-per-view buys of all time (4.4 million) and grossing more money ($600 million) than any other PPV in history. Mayweather made at least $220 million for that fight, and while the rematch wouldn’t be nearly as anticipated, the 38-year-old would likely stand to make another nine figures.

Many found the fight to be "boring" due to a lack of power punches, and after the prolonged build up. In a question-and-answer chat on ESPN's "SportsNation," boxing expert Dan Rafael was asked if he thought a Mayweather-Pacquiao rematch could happen. Rafael replied: "I have no idea. I hope not. I have no desire to go through that again."

Though a rematch will likely make less than the first fight, Mayweather and Pacquiao would be leaving a great deal of money on the table by not fight again. In the final throes of their careers, it would have to be tempting for both boxers to fight, and in the new Las Vegas arena that is set to be complete by early 2016.

But if anyone can afford to turn down another huge payday, it’s Mayweather. He’s made more money than any fighter in the history of the sport, and he claims he earned upwards of $70 million in Saturday’s fight against Berto. Mayweather’s career earnings have now reached $700 million.

Mayweather’s defensive style of boxing hasn’t only been about winning fights. It’s also been about self-preservation. Mayweather has looked to make sure that he stays injury-free, and he could be looking to get out while he still has his health.

This isn’t the first time Mayweather has announced his retirement. The boxer initially called it a career in June 2008, but he was back in the ring a little more than a year later, beating Juan Manuel Marquez. Mayweather returned for a $10-million guarantee, and a much larger purse would be waiting for him upon a second comeback.