Mayweather claims he can't pay 2015 taxes until after McGregor fight

Floyd Mayweather has earned an estimated $700 million from his boxing career, but he says he can't pay 2015 federal taxes he still owes until he gets his check for boxing Conor McGregor.

Mayweather filed a tax court petition July 5 asking the IRS to grant him a temporary reprieve, according to ESPN's Darren Rovell.

The petition notes that Mayweather has "substantial" assets but they are "restricted and primarily illiquid," adding that he has a "significant liquidity event scheduled in about 60 days."

2015 is the year Mayweather earned an estimated $220 million for fighting Manny Pacquiao.

Mayweather is expected to earn about $100 million for fighting UFC champion McGregor on Aug. 26.

It is not known how much Mayweather owes the IRS.