According to Golden Boy Promotions CEO Oscar De La Hoya, who promotes WBC, WBA middleweight world champion Canelo Alvarez, his fighter is dead serious about setting up a rematch with Floyd Mayweather.

And De La Hoya says Floyd has more than a BILLION reasons to make it happen.

"First of all, Floyd is retired so there is no fight to make. But if Floyd did want to come back, he should stop fighting fighters who are two weight divisions smaller than him. If Floyd Mayweather decides to come back, a fight with him and Canelo could be a $1.5 billion fight," Oscar tells TMZ Sports.

Of course, Canelo and Floyd initially fought in 2013 -- with Floyd dominating the then-23-year-old rising star. Floyd got a $41 million guarantee for that fight, which was a record payday at the time.

But, things have changed in a big way since then. Mayweather claims to have made more than $300 million per fight for his bouts with Manny Pacquiao and Conor McGregor.

Canelo's value has also gone way up -- he recently signed a $365 million, 11 fight contract with streaming service DAZN after notching impressive wins over stars like Miguel Cotto, Amir Khan, Julio Cesar Chavez Jr. and Gennady Golovkin.

De La Hoya says he's realistic about the chances of making the rematch happen -- and even takes shots at Mayweather for taking easy fights against hugely overmatched opponents like kickboxing star Tenshin Nasukawa.

Outside of his exhibition against Nasukawa on New Year's Eve, Mayweather has been away from an actual sanctioned boxing match since August of 2017, when he stopped McGregor in a cross sport fight. And that was his first sanctioned fight since September 2015, when he retired after dominating Andre Berto.

But, Canelo says he's out for revenge -- and hopes he can convince Mayweather to strap on the gloves for one final fight.

"I would love to have the opportunity to avenge that defeat," Canelo told us through a translator. "But if it doesn't, then I will continue my path and write my own history."

In the meantime, Canelo is gearing up for his May 4 fight against Daniel Jacobs to unify the WBC, WBA, IBF middleweight belts at the T-Mobile Arena in Las Vegas.