Floyd Mayweather Jr will 'kill' Conor McGregor if the pair clash in a boxing match later in 2017, according to UFC light heavyweight champion Daniel Cormier. Both parties are locked in negotiations over a possible bout but a financial agreement is yet to be agreed.

Mayweather has not fought competitively since September 2015 but has confirmed his willingness to come out of retirement to face either McGregor or another opponent. McGregor is on a hiatus of his own from MMA but has made no secret of his desire to face the 40-year-old.

McGregor's stunning KO record, which has seen him secure victory inside the distance 18 times in his 21 victories – including in 13 seconds against Jose Aldo in the fastest finish to any UFC title bout – has provoked much debate over who would prevail in a potential clash. But Cormier is under no illusions over the challenge McGregor would face.

"Floyd kills him," Cormier said, according to ESPN. "Conor McGregor can't box Floyd Mayweather. Let's be real with ourselves. Neither one of these guys can do the other guy's sport."

Central to negotiations to reaching a resolution is the purse split, talks which have been made more complex by the UFC's intention so take half of the money which McGregor earns from the fight. Mayweather wants a $100m minimum to come out of retirement but given the numbers potentially on offer, McGregor has been urged to take the fight and attempt to survive an onslaught from the former five-division world champion.

"It is pretty easy," the 38-year-old added. "In MMA, Conor McGregor smashes him, kills him. If they fought in an MMA fight Floyd wouldn't last two minutes. In boxing, Floyd kills him. Conor McGregor can't box Floyd Mayweather. Let's be real with ourselves. Neither one of these guys can do the other guy's sport.

Conor McGregor
McGregor is bidding to secure a cross-code clash which would be the first in history. Getty Images

"Floyd Mayweather is in a financial position where he will have to make the rules. Conor is going to have to go to him so Conor is going to get beaten. It's looking more and more likely. A lot of it depends on what piece of the pie the UFC takes and if Conor's number wants to go up because the UFC is taking a portion of it. It's all on Floyd's terms.

"Even if Conor was to fight for $50m and the UFC took $20m, you don't make a $30m pay day in MMA. You just don't in one fight. It's still more money than he ever makes I say go do it and to win all you've got to do is stand up. All he has to do is not get knocked out and he wins."