Matchroom Boxing promoter Eddie Hearn has agreed with Deontay Wilder's assessment of Anthony Joshua's major weakness.
Joshua will take on Joseph Parker on 31 March in a title unification fight with the victor leaving Cardiff with the WBA, IBF, IBO and WBO heavyweight titles.
WBC title-holder Wilder will be in line to face the winner, provided he defends his title against Luis Ortiz on 3 March.
Previously giving his assessment on the title unification fight, the "Bronze Bomber" claimed Joshua would have to work on his conditioning against Parker as he has notably gassed out in his recent wins, mainly due to his large frame and the amount of muscle he carries.
Hearn, who promotes Joshua, is surprisingly in agreement with Wilder but adds that the difference is "AJ" has managed to recover and still keep his 20-0 unbeaten record intact.
"I think Deontay probably has a point in that if there's one weakness of Anthony," Hearn told RadioLIVE via Newshub.co.nz. "He's [Joshua] shown in a couple of his fights in his career where he has emptied his tank at certain moments but has also recovered very quickly.
"Those being in the third round against Dillon Whyte, and the fifth round against Klitschko, where he over-celebrated a knockdown, probably threw over 100 punches in a combo, and emptied his tank.
"That was inexperience. That was work-rate, the fact he was carrying too much weight, nervous energy, everything. It's all things you learn from. What he did do was he came back like a lion and stopped Wladimir Klitschko in the 11th round. Against [Carlos] Takam he went 10 rounds with a busted nose and wasn't really even breathing."
In addition, Hearn pointed out, Joshua has never needed to go the distance with finishes in all his fights unlike Parker, who has won his last three fights via decision. However, he gave credit to the New Zealander for his ability to come strong even in the latter rounds.
"I do give credit and I think Parker may have shown more fitness over a 12-round period, especially with Anthony not even doing 12 rounds," Hearn added.
"They fight in very different ways, Joshua is an explosive fighter, and Parker is not or hasn't shown to be an explosive fighter in his last few fights.
"He's actually shown to be a little bit incumbent and lethargic in his approach, particularly against [Hughie] Fury because that was more out of frustration than anything else so I'm expecting a different Joseph Parker in this fight."