By Keith Idec

Those that were trying to lure Floyd Mayweather Jr. out of retirement obviously made him a financial guarantee for his fight against Conor McGregor that even the extremely wealthy Mayweather couldn’t refuse.

The 40-year-old Mayweather is expected to earn more than $100 million for a single fight for the second time in two years when he meets McGregor in a 12-round, 154-pound boxing match August 26 in Las Vegas. Exactly how much Mayweather (49-0, 26 KOs) and McGregor (21-3, 18 KOs in MMA) will make for McGregor’s boxing baptism might never be divulged, though.

Leonard Ellerbe, chief executive officer for Mayweather Promotions, and UFC president Dana White wouldn’t discuss financial details during a conference call Wednesday night.

They wouldn’t mention their purses or their percentage splits for a fight that they expect to at least approach the roughly $600 million in overall revenue generated by Mayweather’s maligned 12-round, unanimous-decision victory over Filipino icon Manny Pacquiao in May 2015 in Las Vegas.

“We have a confidentiality clause in place,” Ellerbe said, “and the financial details will not be disclosed.”

Official purses for Las Vegas’ Mayweather and Ireland’s McGregor will become available August 25, at the weigh-in for their fight, as per Nevada State Athletic Commission rules. Those listed purses won’t reflect how much money Mayweather and McGregor will make overall off the event, perhaps not even an accurate account of how much each fighter actually is guaranteed.

White has estimated McGregor could make $75 million – much, much more than he has ever made for a UFC fight – and Mayweather would make $100 million for their fight. All White would say Wednesday night was, “Nobody’s bummed out about this deal. I promise you that.”

Ellerbe agreed and added, “Everybody’s happy.”

Mayweather was paid $100 million the night of the Pacquiao fight. He has since hinted that his final take from the heavily hyped, ill-fated fight approached an astounding $300 million.

The Grand Rapids, Michigan, native didn’t start taking a fight against McGregor seriously until he realized he could command another nine-figure guarantee for facing UFC’s biggest star in a boxing match.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.