Khabib Nurmagomedov and Floyd Mayweather seem serious about meeting in the boxing ring.

Many fight fans thought the Russian UFC lightweight champion was kidding when he called out the Money Man on Leonard Ellerbe's Instagram.

"Let's go, Floyd, we have to fight now," the 30-year-old fighter said on camera. "50-0 versus 27-0, two guys who have never, never lost. Let's go. Why not?"

Mayweather responded positively to his callout, stating that he wanted to help make Las Vegas great again.

Nurmagomedov recently recorded the biggest victory of his career at UFC 229 over Conor McGregor.

The Eagle also sparked a mass brawl after he tapped The Notorious out in the fourth-round, leaping out of the Octagon to attack Dillon Danis.

He's set to receive significant punishment from the Nevada State Athletic Commission, who are still withholding his $2m purse.

Nevertheless, Nurmagomedov is eyeing up big fights as soon as possible and a boxing match against Mayweather would be one hell of a pay day.

McGregor himself made the step into boxing to fight the American and despite losing, he grew his following and made some serious money.

And UFC light heavyweight and heavyweight champion Daniel Cormier believes Nurmagomedov would face the same fate as McGregor if he fights Mayweather.

“Khabib better not try to box him. Khabib better not try to box Floyd Mayweather. What is he doing, man?’ Cormier said on Ariel Helwani’s MMA Show.

“Unless he’s just going to go do it for money, because he is going to get beat. I love Khabib man but he is going to get beat up by Floyd Mayweather.

"He’s crazy. He is going to start wrestling. Khabib is going to start wrestling in the boxing ring. He’s going to get beat so bad he is going to start wrestling.”

Do you agree with Cormier and think Khabib would fail against Mayweather in a boxing ring? Let us know in the comment box below.