Anthony Joshua's career-defining rematch with Andy Ruiz Jr could be decided by the challenger's ability to recover from the mental challenge of the first defeat of his career, promoter Eddie Heard has predicted.
Questions have surrounded Joshua's mindset since he was knocked down four times in a seven-round knockout defeat by the quick-handed Mexican-American, with the manner of the shock loss compounding concerns over his capacity to regain his four heavyweight titles.
Hearn, who has partnered Joshua in a close business and personal relationship spanning much of the 30-year-old's career, has praised his fighter's response to his nightmare night in Madison Square Garden on June 1.
Eddie Hearn (fourth from right) has praised Anthony Joshua's mentality ahead of his next fight
Joshua has faced questions around his approach in the build up to rematching Andy Ruiz Jr
Joshua was concussed as Ruiz Jr put him down four times in his shock win in New York in June
Describing Joshua as 'very happy' since touching down in Saudi Arabia, where he will fight Ruiz Jr at the custom-built Diriyah Arena on Saturday, Hearn told Sky Sports: 'He's trained hard and is just tapering down now, probably getting his last sparring in.
'It took him a while to get over the defeat - he had to ask himself some questions, but the way he has bounced back is admirable.
'He's put absolutely everything into this camp and couldn't have tried any harder.
'This isn't a guy shirking a challenge. It's not a guy asking for an easy warm-up fight.
'Creating a legacy has been the motivation and I believe he will win and when he does, it will be sweet.
'Time and time again, he has gone in at the deep end before his time, he's doing it again. A warm-up fight is not in Anthony Joshua's vocabulary.