Watch Anthony Joshua in training for comeback fight as heavyweight star vows to 'keep hustling' ahead of 2023 return | The Sun

ANTHONY JOSHUA vowed to "keep hustling" ahead of his proposed 2023 boxing return.

The former heavyweight champion faces a rebuilding job following consecutive losses to Ukrainian great Oleksandr Usyk.

And he is already back to work in the gym, posting a clip shadow boxing with the caption: "KEEP HUSTLING."

AJ's promoter Eddie Hearn had earmarked December 17 as a potential return date after talks to fight Tyson Fury two weeks earlier collapsed.

But now according to Boxing Scene, Joshua's comeback fight looks more likely to land in February or even March.

Recently, Swedish southpaw Otto Wallin, 31, and American veteran Chris Arreola, 41, emerged as potential options for AJ.

A rematch with Dillian Whyte, 34, who Joshua knocked out in 2015, is also on the cards for the summer.

Fury, 34, called out AJ after Usyk, 35, ruled himself out of a unification bout through injury.

But he instead fights Derek Chisora, 38, in an unpopular trilogy on December 3 following his prior one-sided wins in 2011 and 2014.

Fury now fears a super-fight with Joshua will NEVER happen, claiming his rival is too tough to negotiate with.

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He told talkSPORT: "They are too hard to work with. Too difficult and you can’t make someone do something they don’t want to do.”

Fury added: “You can’t make a fight that somebody else doesn’t want.

“No matter how much willing I am to make a fight, if the other participant doesn’t want to do it for whatever reason, they are not going to do it.

"I don’t believe you could have dragged him there with a JCB. It’s a lack of balls.

"If you are in charge and you’re assertive and you’re the man of your team, you tell the team to make the fight happen if you really want it.

"If you don’t want it, you find a million excuses why.”