Floyd Mayweather appears to have backed out of a planned New Year’s Eve fight with Japanese kickboxing star Tenshin Nasukawa less than three days after he appeared at a Tokyo press conference announcing the bout, claiming he was “blindsided” by the promoter regarding the nature and magnitude of the event.

The five-division boxing champion said in an Instagram post on Wednesday that he had agreed to a three-round exhibition “purely for entertainment purposes with no intentions of being represented as an official fight card” and was “completely derailed by the new direction this event was going”.

On Monday, the Rizin Fighting Federation, a Japanese mixed martial arts company, announced Mayweather would fight Nasukawa, the undefeated 20-year-old kickboxing prodigy, during an hour-long press conference in the downtown Tokyo district of Roppongi attended by the American boxer and One Entertainment CEO Brent Johnson, the marketing executive who helped broker the deal and a relatively new face in Mayweather’s tight-knit inner circle.

The fight between Mayweather and Nasukawa was to headline the Rizin 14 card that had already been scheduled for 31 December at the Saitama Super Arena outside Tokyo, but key stipulations including the contracted weight, number of rounds, type of gloves and – crucially – the rule set under which the bout would take place were left unannounced.

When pressed over the details during Monday’s press conference, Mayweather appeared unconcerned, saying: “We’ll talk about that, we’ll get that situated within the next couple weeks. As far as the weight class, we’re not really worried about that. When it’s all said and done, it’s all about me going out there and displaying my skills against another skillful fighter.”

Added Johnson: “We put this together very quickly but with a great deal of professionalism and we look forward to keeping that going for the rest of our tenure together, however many years that may be.”

But in Wednesday’s statement Mayweather implied he was ambushed, admitting that “we should have put a stop to it immediately” but he was “hesitant to create a huge disturbance”.

“I want to sincerely apologize to my fans for the very misleading information that was 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 nor approval,” Mayweather said.

Several phone calls and messages to Mayweather, Johnson and Leonard Ellerbe, the fighter’s longtime manager, were not immediately returned on Wednesday.

A video promoting the fight posted to Rizin’s official public relations Twitter account roughly four hours before Mayweather’s announcement had not been removed as of Wednesday evening in the United States.

A direct message to Rizin’s staff account requesting clarification on the promotion, including whether a contract had been signed, was not immediately returned.

The prospective showdown between Mayweather and Nasukawa had quickly drawn comparisons to the 1976 fight between Muhammad Ali and Japanese pro wrestler Antonio Inoki. The crossed signals described by Mayweather on Wednesday, whether innocuous or deliberate, offer an even deeper parallel, as related by the Guardian’s Andy Bull in 2009:

“[A]ccording to Inoki’s version of the story, Ali and his entourage had signed on expecting the fight to be an exhibition rather than a real contest. It was only when they went to see Inoki train, and watched him break and twist a series of sparring partners with a series of brutal drop-kicks and violent grapples, that the truth dawned. ‘OK, so when do we do the rehearsal?’ Ali supposedly asked Inoki, only to get the answer: ‘No, no. This isn’t an exhibition. It’s a real fight!’”

Mayweather, who turns 42 in February, captured world championships in five weight classes, but has not fought since a 10th-round knockout of UFC star Conor McGregor under boxing rules in August 2017.

He announced his retirement immediately afterward with a 50-0 record as a professional, but has since teased comeback fights against old nemesis Manny Pacquiao and UFC lightweight champion Khabib Nurmagomedov.

For now, it seems, Mayweather is content to pump the brakes on his fighting career.

“I am a retired boxer that earns an unprecedented amount of money, globally, for appearances, speaking engagements and occasional small exhibitions,” he said Wednesday.