LOS ANGELES • Floyd Mayweather said on Wednesday that he never agreed to come out of retirement to fight a Japanese kickboxer on New Year's Eve and was blindsided when the event was announced this week at a news conference he attended in Tokyo.

The American said on his Instagram account that he agreed only to a three-round exhibition in front of a small group of wealthy spectators for a very large fee with no intention of it being represented as an official fight card or televised worldwide.

"Once I arrived to the press conference, my team and I were completely derailed by the new direction this event was going and we should have put a stop to it immediately," he wrote.

"I want to sincerely apologise to my fans for the very misleading information announced during this press conference and I can assure you that I too was completely blindsided by the arrangements that were being made without my consent or approval."

The 41-year-old added that he had been reluctant to create a disturbance at the news conference by combating what was said for the sake of what he described as several fans and attendees who had flown in from all parts of the world to attend the event.

The American also said he has no plans to put his unblemished mark on the line.

At the news conference, it was announced that Mayweather would top the bill at Japanese mixed martial arts promotion Rizin Fighting Federation's next card on Dec 31 against a Japanese kickboxer in Saitama with the rules yet to be determined.

His opponent was introduced as Tenshin Nasukawa - a 20-year-old who competes in both MMA and kickboxing and has won all four of his cage fights.

"I want it to be clear that I never agreed to an official bout with Nasukawa," Mayweather said.

But Yahoo Sports columnist Kevin Iole greeted the boxer's volte-face with scepticism.

"Mayweather is hardly a shrinking violet and he has never - ever - failed to speak up on his own behalf since he became a professional boxer," Iole wrote. "One would have to be a fool to believe this."

REUTERS, AGENCE FRANCE-PRESSE