Floyd Mayweather issued warning by UFC 219's Holly Holm about 'whole different world in MMA'

UFC 219 headliner and former boxing champion Holly Holm has warned Floyd Mayweather that should he decide to explore his MMA options, he will have to prepare for a whole new world.

The combat world was sent into a frenzy after Mayweather revealed he could make a billion dollars by fighting in the octagon, and reports emerged that UFC president Dana White was in talks with the former five-weight world champion.

A rematch with Conor McGregor, who "Money" invited into the boxing world when he defeated the Irishman in August, would be the most ideal and lucrative option for the duo, with both making nine-figure paydays from their first meeting.

However, Mayweather shut down those reports, stating that while he could make a billion dollars through MMA, he has no current plan of doing so.

Holm will take on Cris Cyborg in the main event of UFC 219 for the women's featherweight title on 30 December. Being one of the few fighters to excel in both boxing and MMA, the former champion offered her perspective on how the transition would be if Mayweather decided to try his luck out in the octagon.

"It is a whole different world in MMA," Holm told TMZ. "I think one of the biggest things that I tell people was the hardest going from boxing to MMA is, kind of that inside boxing.

"You'd get comfortable sitting in the pocket wanting to throw punches, and you'd have this other person coming at you and just clinches onto you. In boxing you clinch a bit and the ref breaks you up, but in MMA (if) they clinch you, they take you down.

"So it doesn't mean that he can't learn it. But it's going to be a whole different gameplan from what he's doing in his boxing career. But I don't put it past anybody to be able to do the transition," she added.

Meanwhile, despite his coach John Kavanagh claiming he is not obsessed with his loss to Mayweather, McGregor has been tweeting recently about the American amid recent reports.