Anthony Joshua is already "physically and mentally" preparing for a rematch with Oleksandr Usyk, a firm rebuttal to Tyson Fury's hopes of securing his own undisputed fight.
WBC champion Fury's "preference" for his next opponent would be Usyk, in a battle to crown the division's No 1 heavyweight, rather than Dillian Whyte, his promoter Bob Arum had told Sky Sports.
But Joshua has rebuffed the suggestion he may "step aside" from his rematch with Usyk.
"AJ is already in camp physically and mentally for the Usyk rematch, and it's all he has thought about since the night of the first fight," his promoter Eddie Hearn told Sky Sports.
"I have a meeting planned with [Usyk's promoter] Alex Krassyuk to start working on proposed venues for the spring rematch.
"It's a huge fight and we believe AJ can become a three-time world heavyweight champion."
Usyk delivered a masterclass to win the IBF, WBA and WBO belts from Joshua who immediately triggered his right to a rematch.
"We have three options under consideration: the UK, Ukraine and the Middle East," Usyk's promoter Krassyuk told Sky Sports.
"Hopefully by the end of 2021, we will be in the position to take the final decision."
A WBC deadline for Fury and Usyk to agree an undisputed title fight has since expired - they were never in talks because of Joshua's swift decision to exercise his rematch clause.
The same WBC ruling claimed, if no deal was struck between Fury and Usyk, then Fury would be forced to face the interim champion, Dillian Whyte.
But the WBC opted not to name a mandatory challenger for Fury this week, despite the expectation that they could end Whyte's long wait for an opportunity.
Fury's US-based promoter Arum told Sky Sports: "Whyte is an excellent fighter. When the time comes, and it will come soon, for Tyson to figure out his next opponent, then Whyte should be at the top of the list."
Arum's suggestion which Joshua's promoter Hearn has now responded to was: "The alternative is that if Joshua decides not to exercise his rematch against Usyk and decides to step aside, the fight we would like to make is between Usyk and Fury," Arum said.
"That is a fight to unify the titles once and for all.
"Then Joshua can fight the winner of the undisputed fight.
"Whyte can stand in line and fight the winner ultimately.
"That's what Tyson would like. And I represent Tyson. That is his preference.
"If they want to fight each other, which I believe they do? I would facilitate it."
Joshua's preparation to face Usyk again has seen him travel to the United States for training sessions with Robert Garcia, Virgil Hunter, Eddy Reynoso and Ronnie Shields.
Sky Sports Boxing schedule
November 20 - BOXXER in London
Richard Riakporhe vs Olanrewaju Durodola
Florian Marku vs Jorick Luisetto
Hosea Burton vs Dan Azeez - British light-heavyweight title
November 20 - Top Rank in Las Vegas
Terence Crawford vs Shawn Porter - WBO welterweight title
December 11 - BOXXER in Cardiff
Chris Eubank Jr vs Liam Williams
Claressa Shields vs Ema Kozin
December 11 - Top Rank in New York
Vasiliy Lomachenko vs Richard Commey
Jared Anderson vs Oleksandr Teslenko
Nico Ali Walsh
December 17 - Top Rank in Montreal
Artur Beterbiev vs Marcus Browne - IBF and WBC light-heavyweight titles
February 26 - Top Rank in Glasgow
Josh Taylor vs Jack Catterall - undisputed super-lightweight title