UFC boss Dana White has given the biggest indication yet that any potential rematch between Conor McGregor and Floyd Mayweather would be in the Octagon.
White urged Floyd Mayweather to put his money where his mouth by following through with a statement to fight the Irishman in a UFC bout.
"Floyd said leading up to the fight with Conor that he would do both. So we'll see what happens," White said on Fox Sports program, UFC Tonight.
While hinting at another mega money-spinning fight between the pair, White said he doubted it would be in the boxing ring again though.
"Obviously, the only way making that fight again makes any sense is if he comes into the Octagon," White said.
"We went over and boxed him, the UFC and Conor McGregor, and now it's time for him to reciprocate and come and fight in the Octagon."
White's comments come after Mayweather teased a potential UFC bout with a series of posts on social media last week.
The American, who hasn't fought since knocking out McGregor in that boxing match last year, got fans' tongues wagging with a photo of himself wearing mixed martial arts gloves and standing in an UFC cage.
"Billion Dollar Man," Mayweather said in the tweet.
Mayweather and McGregor's cross-combat fight in August failed to live up to the hype in the ring as veteran Mayweather easily outpunched the inexperienced McGregor, but it did well at the box office.
The contest generated 4.3 million pay-per-view buys in North America, trailing only Mayweather's 2015 world title boxing match with Filipino Manny Pacquiao that generated 4.6 million buys and earned $600 million.
It is the second time in a week Mayweather has teased his fans with the idea. The undefeated boxer also posted video on Twitter and Instagram of himself shadow boxing in a cage.
He said "Come at the king, you best not miss..."
Mayweather's August fight with the Irishman was supposed to be his last as it secured his perfect 50-0 record. But the American has retired several times only to negotiate "comeback" fights for bigger paydays.
There's no doubt a rematch with McGregor - albeit in UFC rather than boxing - would again be one of the biggest pay days for both fighters.
But if the majority of fighting experts are correct, it would basically be the first time in 50 fights that the American goes into the bout as the clear underdog.