Anthony Joshua may have to wait for his shot at Tyson Fury after the WBO insisted they will force him to face his mandatory challenger first.
Joshua and Fury have agreed terms on a deal to fight twice in 2021 in order to establish the first undisputed heavyweight world champion since Lennox Lewis 20 years ago.
But there are several hurdles remaining before they can touch gloves with Fury due to face Deontay Wilder this winter and Joshua preparing for his clash with Kubrat Pulev.
Should Fury win his trilogy clash with Wilder he could then be forced to face mandatory challenger Dillian Whyte early next year.
And the WBO are ready to insist Joshua takes on the winner of Oleksandr Usyk's fight with Dereck Chisora.
The organisation's president Paco Valcarcel tweeted: "Love to see WBO unified champion Anthony Joshua fighting WBO former and current WBC champion Tyson Fury for the undisputed heavyweight champion of the world, but WBO mandatory should be next."
Usyk, who was the undisputed cruiserweight world champion before he moved up a division last year, was due to face Chisora in May but the fight has been delayed due to the coronavirus crisis.
It is still expected to take place this year but the rivals are set to wait for crowds to return to venues before finalising the bout.
And the Ukrainian's promoter has no plans to ask his fighter to then step aside to allow Joshua and Fury to meet.
"Usyk [claimed] his highest achievement at cruiserweight in order to obtain the mandatory position at heavyweight," Alexander Krassyuk told Boxing Scene. "And as his promoter, the fairest thing I can do for him is ensure that his sacrifice has not been made in vain.
"We must deliver the heavyweight championship fight for Usyk as fast as possible and we will stand our ground."
