Oleksandr Usyk could face Filip Hrgovic after the collapse of his clash with Tyson Fury.
Fury and Usyk had been expected to arrange an undisputed clash for the end of April, but there is a chance not just that the date is now too soon to be used, but a fight between the pair may now never happen.
As unified champion, Usyk’s WBA, WBO and IBF belts each come with a mandatory challenger, and Hrgovic is the heavyweight nominee for the IBF after defeating Zhilei Zhang in an eliminator bout.
The Croatian is keen to make a fight if one is available, and his promoter Kalle Sauerland said he is ready to step up.
"Usyk, Hrgovic is waiting for you, the rest of the belts, he wants them all," Sauerland said to Sky Sports.
"He's not the type to beat round the bush, Filip. He's been waiting a long time for this shot.
"After the whole of the IBF top 15 didn't want to fight him, hats off to Zhang.
"He's next in line to fight Usyk [for the IBF title].
"Who doesn't think that Hrgovic would give any heavyweight a right run for his money?
"I'm going back to the fact that he stopped David Haye from taking part in the David Haye-Tyson Fury fight. He was the one who gave the left hook in sparring that took him out of that fight, unfortunately.
"There's the leaked sparring with Deontay Wilder.
"It's a right back and forth. It's pay-per-view boxing in sparring.
"For people who know their boxing Hrgovic is obviously a massive, massive fight at heavyweight.
“It's a fight that I think a lot of people want to see," Sauerland said.