UFC superstar Conor McGregor has plenty of time today. The MMA fighter hit up social media to rip boxing rival Floyd Mayweather Jr. on his comeback fight announcement.

McGregor went to Instagram to poke fun at Mayweather making his return overseas in Japan.

A few hours ago, Floyd’s estranged pal 50 Cent flamed Mayweather on his comeback.

According to reports, Mayweather’s decision came shortly after he signed a new promotional deal.

The boxer announced his decision after signing for mixed martial arts promotions company RIZIN Fighting Federation. Mayweather has never fought in MMA before and the format for the Nasukawa fight has not yet been confirmed. “I wanted to do something different,” said the former five-weight world champion. (CNN)

Mayweather’s opponent is more than half his age and has an impressive career record.

Japan’s Nasukawa, 20, competes in the RIZIN Fighting Federation, the company Mayweather has signed with, in both kickboxing and mixed martial arts. “It was a surprise offer but I accepted without hesitation,” said Nasukawa, who has a 27-0 record in kickboxing and a 4-0 record in MMA. (BBC)

Recently, 50 Cent trolled Floyd about coming out of retirement solely for money purposes.