Mayweather won that bout courtesy of a unanimous decision. Since then, both fighters have called the other out on social media, but a deal has never quite been finalised between the two megastars.
However, according to SunSport, Mayweather has an added incentive to seek a rematch with the Philippine fighter as soon as possible.
That's because the 42-year-old American is looking to build a casino empire out in Asia and a rematch with Pacquiao in Japan would be the perfect way to start the campaign.
Back in June, Mayweather launched TMT Japan in Tokyo, as well as his partnership with management company Libera and Kyoei boxing gym.
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Hong Kong based promoter Jay Lau told SunSport: "In Asia more and more casinos are setting up.
"Mayweather came to Tokyo to set up TMT Japan because of the Japan casinos that open in the next year.
"There are casinos opening in Cambodia, Singapore and China as well. It means boxing will get more and more popular.
"The Manny rematch is the biggest thing that can happen. I hope it does happen, it could be a big possibility that fight is the grand opening for the Japan casinos."
Lau went on to reveal that Mayweather has put the brakes on any potential exhibition fights in the near future as he is solely focused on securing the Pacquiao rematch.
The promoter said: "Mayweather came two times to Hong Kong, he spoke with my son Jayson and we had communications but now he is focusing on the Pacquiao rematch.
"We were talking about an exhibition in China, a big event but not a recorded professional boxing fight. Something like Mayweather vs Tenshin in Japan.
"We spoke a bit about doing a special fight in China, but half way through he turned to the Pacquiao rematch so we stopped."
Given Pacquiao is still an active world champion and Mayweather's last bout was an exhibition against Tenshin Nasukawa, the Philippine would surely go into the rematch as the favourite.
In his last fight, Pacquiao defeated fellow welterweight champion Keith Thurman, proving that he is still one of the best in the game.
Does he really need a rematch with Mayweather when there's the prospect of a unification bout with Terence Crawford down the line? We'll have to see if the money does the talking...News Now - Sport News