Floyd Mayweather offers Conor McGregor $15m to fight him in the boxing ring

'How can a guy talk about making 20 or 30 million if he has never made 8 or 9 million in a fight?'

Mayweather retired with an undefeated 49-0 record (Getty Images)

Floyd Mayweather has made a counter offer of $15m (£12.2m) to fight UFC champion Conor McGregor in the boxing ring.

McGregor had previously said he wanted $100m to switch codes but Mayweather told ESPN that figure is too high.

"We tried to make the Conor McGregor fight. They know what my number is. My number is a guaranteed $100 million. That was my number," Mayweather told the site.

"We are willing to give him $15 million and then we can talk about splitting the percentage - the back end - on the pay-per-view. But of course, we're the 'A side.' How can a guy talk about making 20 or 30 million if he has never made 8 or 9 million in a fight."

The five-weight boxing champion retired from the sport with an undefeated 49-0 record but says the prospect of a fight with the Irishman might tempt him to put his gloves back on.

“You guys keep hearing all these different rumors about different fighters want to face Floyd Mayweather," he said. "Everybody keeps talking about Conor McGregor. He's blowing smoke up everybody's a**. Dana White, the UFC - let's make it happen. Bring him over to the boxing world, and I'll show him what it's like.”

McGregor made the reality of the much-anticipated fight a step closer last month after obtaining a boxing licence so he can fight professionally in California.

It remains to be seen if he will accept the reduced offer from Mayweather, although it would represent a significantly higher purse than the $3m he took in his UFC 202 fight against Nate Diaz in August - itself a record in his sport.