Tyson Fury is unconcerned about his rematch with Oleksandr Usyk losing its status of being an undisputed heavyweight title fight, according to his manager Spencer Brown.

Fury in May lost to Usyk in the first undisputed heavyweight title fight for 25 years when, as a fighter who makes little secret of his admiration for his profession’s history, he had spoken of his ambition of earning the status last enjoyed by the great Lennox Lewis.

Fury lost the most entertaining of fights and swiftly agreed to a rematch on December 21, but Usyk vacating the IBF title and it since being awarded to Daniel Dubois means that even if he avenges his only defeat and records his biggest victory he will emerge only with the WBA, WBO and WBC titles.

As recently as Wednesday his long-term rival Anthony Joshua, who is challenging Dubois on September 21 at Wembley Stadium, spoke of the satisfaction he is taking from contributing to denying Fury the opportunity to win the undisputed title, but Brown, who has talked to his fighter regularly since the defeat by Usyk, said: “Tyson’s not really bothered about it. The last couple of weeks, he’s enjoying himself. He’s having a great time in his life with his kids, and he just wants to put boxing behind him. Does a belt bother him? No.