Joshua fights WBO mandatory challenger Oleksandr Usyk (18-0, 13 KOs) in London on September 25 and Fury vs. Wilder III on October 9 in Las Vegas.
"Joshua's opponent after Usyk fight? All that matters is that he will have the WBC belt. We've never sought a fight against Fury or Wilder, we've always been only interested in the title of undisputed champion," Hearn said.
"I have a terrible feeling the Fury vs Wilder III fight won't happen on October 9. I hope this duel happens, but I'm not sure. And AJ has to deal with Usyk. It's a very, very tough fight. Whoever wins he will face Fury or Wilder for the last of the belts," added the head of Matchroom Boxing.