The clock is still ticking to finalize a unification showdown between heavyweight champions Anthony Joshua and Deontay Wilder.
Their contest was initially targeted for September 15 at Wembley in London - but that date is apparently out the window as the negotiations have continued to drag out - and to make matters worse the Gennady Golovkin-Canelo Alvarez rematch was finalized for the same date on HBO Pay-Per-View.
Because of the scheduling issues, the fight - if finalized - would be more likely for a date in October or November.
Hearn wants Joshua to have a proper training camp for this contest - so he won't allow the IBF, IBO, WBA, WBO world champion to fight Wilder with a shortened camp.
He feels an eight week camp would not be enough for a fight of this magnitude.
"I'm not letting Anthony Joshua fight this fight with an eight-week camp, because this is everything, this fight," Hearn told Sky Sports.
"Everything that he's built towards, his whole professional career, maybe his whole boxing career is built towards this moment. We're not just going to go 'oh yeah, let's just dive in and do it on a date that doesn't give us the best prep time.
"I think more realistically, October, November is a solution, but that does rule out the place where we wanted to stage it, which is Wembley, so lots to try and resolve, but we want the fight, we're prepared to sign for the fight now. They'll see the contract, they won't see anything out of the ordinary, then we'll go from there."
Joshua and his head trainer Rob McCracken are getting impatient and want their next opponent set down - whether it's Wilder or a mandatory defense against WBA challenger Alexander Povetkin of Russia.
"They want to get moving," said Hearn. "They boxed the 31st of March, so he's had a nice break. He's sort of just started ticking over now, but they would like to know. They would like a decision. They feel like Povetkin is a very, very tough fight. They feel like Wilder is a very, very tough fight, but AJ is up for fighting them both."