Former two-division world champion David Haye believes an undisputed fight, in the heavyweight division, has a good chance of coming off if Daniel Dubois pulls off a major upset against Oleksandr Usyk.

Dubois will challenge Usyk for the WBA, IBF, IBO and WBO titles on Saturday night in Poland.

The remaining belt, under the WBC, is held by Tyson Fury.

Negotiations to make a Fury vs. Usyk undisputed fight have failed in the past due to disagreements over money.

However, Dubois and Fury are both promoted by Frank Warren of Queensberry Promotions.

“It feels like we’ve had three or four opportunities where the fighters with the belts could have come together and done a deal. For whatever reason, it hasn’t materialized," Haye told PA Sport.

“We’re in a position where if Dubois wins on Saturday night, one promotional entity holds the champions of all of the belts – there would never be an easier time, politically, to make the undisputed fight.

“If Usyk wins, is Tyson Fury ever going to fight Usyk? I don’t know. For one reason or another, it doesn’t seem like it’s gelling. If it hasn’t happened by now, is it going to happen? Probably not. We want to know who’s number one. If Dubois wins then that makes it possible and the fight fans finally, after all of these years, will have one champion with all of the belts.”

Getting to the victory line is a tall order for the bigger Dubois.

In his last fight, back in December, he was dropped three times by Kevin Lerena. Dubois and his handlers would argue that two of the knockdowns were the direct result of a knee injury. Dubois would later undergo knee surgery.

“I like the fact there’s no pressure on Dubois whatsoever. He’s got everything to gain. Nobody is expecting him to be able to cause an upset here. He has the firepower, all he needs is one punch, one clean shot," Haye said.

“He had a very interesting fight against Kevin Lerena where he was put down early from a southpaw who was a former cruiserweight. He understands that he’s bigger and stronger but he can be hurt, that was the best thing for him because it gives him the reality of what he’s putting himself in (when he takes on Usyk).

“It looks from the outside like a mission impossible but I’m liking what I’m hearing from him – he’s talking about making it rough and uncomfortable for Usyk and that’s exactly what he needs to do. He may get dropped or hurt or some facial damage but he’s going to need to work through that to get to the promised land if he wants an opportunity to seriously gatecrash the heavyweight division.”