Joshua's defeat to Oleksandr Usyk last week seemingly left Warren's plans in ruin as it scuppered a potential British super fight with Tyson Fury but the Hall of Fame promoter said it would still appeal to boxing fans despite the result.
Warren also questioned why some Sky Sports pundits still refer to AJ as a prospect and said he simply 'got beat by the better man on the night'.
"I do believe the public buys into that fight even if AJ isn't champion," Warren told BBC Sport.
"AJ's said a lot of things since the fight [and] a lot of nonsense from 'doctor' [Eddie] Hearn about his eye.
"You got beat by the better man on the night and Joshua said that, to his credit.
Anthony Joshua is the former unified heavyweight world champion (Picture: Getty)
"Joshua is a big fight. They keep talking about him still learning. He's 32 years old. He's an Olympic champion and world champion.
"Of course you can still learn every day, but at that level, at 32 years of age, with the experience you've got and the amount of professional fights you've got, if you're not absolutely world class at that level then you're never going to be.
"But having said that, if he did fight Tyson he would have a lot to prove and I do think the public would buy into it."
Fury, 33, will defend his WBC and Ring magazine heavyweight titles against Deontay Wilder at the T-Mobile Arena in Las Vegas.
With Wilder out of the picture, Warren reckons Fury will return home to a hero's welcome in the UK.
"There's no Yanks out there for him to fight," he added.
"I think he'll be back here which will be a great homecoming.
"If Tyson wins the fight we'll sit down.
"There's a few options there. Usyk would be a massive fight here. The Joshua fight is still a massive fight.
"Dillian Whyte is a big fight, providing he beats Otto Wallin which isn't a foregone conclusion. There's some big fights for him."News Now - Sport News