Mayweather ready for Japan fight, whatever the rules

Undefeated boxer Floyd Mayweather Jr. of the U.S. shakes hands with his opponent Tenshin Nasukawa during a news conference to announce he is joining Japanese Mixed Martial Arts promotional company Rizin Fighting Federation, in Tokyo, Japan November 5, 2018. REUTERS/Issei Kato

TOKYO (Reuters) - Floyd Mayweather has won world titles in five different weight classes and is 50-0 in an unparalleled boxing career but the American could be set for a stunning detour into the world of mixed martial arts after signing with Japanese promoters RIZIN Fighting Federation.

And the undefeated 41-year-old, who last year said his boxing career was over after beating Irish MMA fighter Conor McGregor, has told Reuters he could handle himself in whatever format was agreed for the fight on New Year's Eve in Saitama.