Unified heavyweight champion Oleksandr Usyk 20-0 (13) has called out WBC counterpart Tyson Fury 33-0-1 (24) for what he sees as a money grab in his next fight.

The 35-year-old Brit is set to face boxing debutant and former UFC heavyweight champion Francis Ngannou in a 10-round non-title bout in Saudi Arabia on October 28.

Ukrainian southpaw Usyk, 36, was in negotiations early this year for a two-fight series with Fury before talks fell apart over the purse split for the rematch.

Usyk conceded a 70-30 split in Fury’s favour for the first fight, but wanted a 50-50 split for the rematch should he come through the bout victorious.

Fury turned down the offer.

In the week leading up to his title defence against mandatory contender Daniel ‘Dynamite’ Dubois 19-1 (18) at Stadion Wroclaw in Wroclaw, Poland on Saturday night, Usyk let his thoughts be known on Fury’s next matchup.

“I think it’s easy money for Tyson Fury,” WBA, WBO and IBF champion Usyk said to BBC Sport. “I think for me it looks a little bit strange, to me, too strange.

“A guy who is WBC heavyweight champion instead of fighting a guy from the top 10, suddenly chooses the guy as his opponent coming from the UFC. For Ngannou, this is cool. But for Tyson Fury, it isn’t. Your perception and my perception are different. You treat it like show, I treat it as an athlete. If he chooses this way, okay, I respect his choice.”

Alexander Krassyuk, who promotes the former undisputed cruiserweight champion, is adamant that Usyk vs Fury must happen not just for the boxers themselves, but for the good of the sport.

“It’s our obligation to deliver this fight,” Krassyuk said to BBC Sport. “The whole world wants to see this fight. Not just ourselves or people involved in boxing, but the whole world.

“People who know nothing about boxing would love to see the heavyweight undisputed fight for the four belts for the first time in the four-belt era. I can promise you and promise all the fans around the world that I will do everything that can depend on me to make this fight happen.”

But Fury’s British co-promoter Frank Warren, who works longside American Bob Arum, scoffed at the notion of Fury facing Usyk.

He is convinced that his boxer Dubois, 25, will defeat Usyk, leading to an all-British showdown with Fury.

“How’s it going to happen when Daniel wins?” Warren said.

“I think our man beats him. Our man beats him and if he beats him then Usyk is out of the picture. Then we’ll see where we go from there.”

Now pushing 37, Usyk knows he does not have time on his side to add to his legacy in the sport. But he disputed suggestions he was on the home straight of his career.

“No, it is not the final point,” Usyk said. “I am 36, but this is just the beginning. I started boxing at the age of 15. It’s just the beginning now.

“I do realise there are not many years left for me in boxing and I don’t want to spend much time in boxing. I want to take my kids to school and whatever.”