Tyson Fury retirement promise made as threat of mammoth £200m lawsuit surrounds Gypsy King

However, Fury's camp is now believed to want more time in order to prepare for that battle.

That's despite reports saying the Brit is at risk of a potential £200million lawsuit if the fight with Usyk doesn't take place on December 23.

And while talk of that potentially happening rumbles on, Hearn has now claimed Joshua would beat Fury - and send the 35-year-old into retirement.

“I’m telling you and I say it with a big chest and all my heart and now all my brain, Anthony Joshua beats Tyson Fury everyday of the week," he told IFL TV.

"He knocks him spark out.

“And you can go around and say he’s frozen out, he’s a dosser, I’m a dosser, whatever.

“We saw on Saturday night, we know the weaknesses, there [points at head] and there [points at chin] aren’t what they used to be.

​“Make the fight, AJ against Fury… You have to make the AJ fight, you cannot retire without fighting Anthony Joshua.

“But, he’ll do the job for you because he’ll put you into retirement, I promise you that.”

Fury has continuously made it clear he has no interest in fighting Joshua.

But when it comes to stepping into the ring with Usyk, his tone has changed.

Fury initially sounded confident it would happen at the original date, saying: “We’ve signed the contracts. 23 December, that’s out there isn’t it?

​"It’s only eight weeks away from Saturday. Why not?

“I’ve not even had a fight this year, so to get two in before the end of the year would be fantastic. Double payday.

"There’ll be a nice big turkey in the Fury household this Christmas!

“If it happens 23 December, I’ll be playing that song, 'Driving Home For Christmas'.

"I won’t land back in the UK until Christmas Eve, late Christmas Eve, and if we get a delay I’ll be spending Christmas with the reindeer in the airport!”

Since his narrow win over Ngannou, however, he's sounded less certain.

"They’ll sort it out when they sort it out," he said.

"Until that day, don’t bother me with boxing.

“I’m going home, I’m going to spend some time with my kids.

“I’ve been away for 12 weeks. I’ve got a newborn baby I’ve seen three times.

LATEST SPORTS NEWS:

• Sir Bobby Charlton cause of death revealed after Man Utd icon died aged 86
• Tyson Fury 'might retire' with boxing star at risk of massive £200m lawsuit
• Championship football club on brink as owner issues brutal statement demanding fans pay him £2m

"He’s six weeks old. I’ve done my job and been paid, happy days.”

If Fury doesn't fight Usyk in December, then it will disrupt Saudi's Riyadh Season.

They have planned a whole six-month event relating to big sporting and entertainment events.

But losing arguably the headline act would be a catastrophic blow.