Undefeated heavyweight Oleksandr Usyk 17-0 (13) could throw a spanner in the works ahead of a proposed four-belt unification bout between WBA, IBF and WBO champion Anthony Joshua 23-1 (21) and WBC boss Tyson Fury 30-0-1 (21).
Joshua is scheduled to face IBF mandatory Kubrat Pulev at Tottenham Hotspurs Stadium in London on June 20, while Fury will go directly into a rematch with Deontay Wilder in July.
Positive discussions have already taken place to pair up the duo in December in a mouth-watering clash to determine the number one heavyweight on the planet.
But Ukrainian southpaw Usyk, who will face gatekeeper Dereck Chisora next, could scuttle those plans if he enforces his WBO mandatory title shot.
Promoter Eddie Hearn was asked whether Usyk might have to wait until 2021 for a world title fight.
“Well, only if Usyk says so,” Hearn told Sky Sports.
“The big problem there is that Usyk must fight the winner of Pulev against Anthony Joshua. The only way he mustn’t is if he waits maybe a month, or maybe there’s an agreement to vacate after. I don’t know, but sometimes things like that are solvable.
“He’s got a little task ahead of him on May 23. He might not be mandatory challenger on May 24, if Dereck Chisora has got anything to say about it. That is a monstrous fight at The O2 Arena. We’ll announce next week in full.”
Joshua revealed he has already begun working on a plan to combat the southpaw style of fellow Olympic gold medallist Usyk, who moved up to heavyweight last year after unifying the cruiserweight division.
“I’ve actually been preparing for a southpaw, because some time down the line, I know I’ll fight Usyk anyway, so the smart thing to do would be to start preparing, start sharpening my tools,” Joshua told Sky Sports.
“That’s the brilliant thing now. I know I’m fighting, like two to three times a year, so it gives me enough time to actually practice and start working on certain aspects.”