The pair will meet in a boxing match on August 26 in Las Vegas
Floyd Mayweather Jr says he came out of retirement to take on Conor McGregor in the boxing ring because it was a fight "the world demanded".
Considered one of the greatest all-time boxers and with an unbeaten record of 49-0, Mayweather will step into the ring against UFC Lightweight champion McGregor - who has never boxed professionally.
The deal, announced last week, will see both fighters enjoy a massive pay-day, but Mayweather said it was the will of the fans and not the money that motivated his decision.
"McGregor is a tough competitor," he told Black Sports Online. "People all around the world demanded this fight so I had to give them what they wanted to see."
Although he didn't disclose the amount of money that each fighter will pocket, Mayweather said both sides were "very happy" with their cut.
He also urged McGregor fans to get behind their man, who is seen as a massive underdog for the fight.