Khabib Nurmagomedov vs Floyd Mayweather is beginning to look like a distinct possibility.
The Russian UFC lightweight champion called out the 50-0 American on Instagram, but many thought it was a bit of a publicity stunt.
However, Mayweather was quick to respond and declare his interest in a bout which would attract attention from all over the globe.
The Money Man is one of the biggest sport stars in the world and Nurmagomedov's standing has grown enormously in the last week or so.
After his fourth-round victory over Conor McGregor in Las Vegas, The Eagle is now a global superstar, with his Instagram following increasing by 6 million since the bout.
It would be an enormous pay day for both Mayweather and Nurmagomedov.
And Khabib's father, Abdulmanap, has now reacted to the rumours, issuing two big demands in the process.
“Khabib will have a chance in boxing, he will have a higher chance than McGregor. Khabib will go close up in the clinch,” Nurmagomedov Sr told TASS.
“I would like the best specialist in the boxing world Anatoly Lomachenko and Mike Tyson to be in our corner."
Iron Mike in the corner? That's one way to add yet more to the Box Office factor.
A switch to boxing could be ideal for Khabib given his issues with the UFC after his attack on Dillon Danis.
However, his uncle, Alex, has stated that he thinks a fight with Tony Ferguson is next on the agenda for the lightweight champion.
"[Conor] is not interested in Khabib," he told Sport Express . "He will not fight him for any money. Yes, I know that they are offering him a rematch. From the start, they offered him $15m, if he agrees.
"But Khabib said no. Let Conor stand in line, let him fight with others. Khbib wants to fight [Tony] Ferguson, and then finish his career."