Anthony Joshua will fight Daniel Dubois for the IBF world heavyweight title on Saturday at Wembley and Frank Warren has issued an early warning.

In an all-British affair, Dubois will defend his belt for the first time against stern opposition when he touches gloves with AJ in the ring on September 21.

And Dubois’ promoter Warren believes that the pre-fight amble is at its tensest stage with the clash just days away.

“Fight week, everybody is on edge. These guys are jumping out of their skin and as fit as they’re ever going to be,” Warren told Sky Sports.

“They know what’s at stake. It’s pretty much a mental game now. Each of them will be trying to get an edge mentally.

“I’m sure something will be said, because that’s the nature of the business.

“Whatever is said, at the end of the day it doesn’t matter. What does matter is Saturday night when they step into the ring.

“When the first bell goes is when you get down to the serious business. When you’re getting hit.”

Wembley will play host to the epic clash, a venue Joshua has not fought at since September 2018 when he beat Alexander Povetkin by technical knockout.

AJ has taken some knocks since then, including a shock defeat to Andy Ruiz Jr and a double-loss to Oleksandr Usyk.

But the 34-year-old has returned to form since, claiming four wins out of four – including two earth-shattering knockouts on Robert Helenius and Francis Ngannou.

And Warren believes it could be a record-breaking event on Saturday with boxing fans keen to see the two Britons fight it out.

An all-British affair. There is nothing more exciting than when two Brits fight, you can look back through the years,” Warren added.

“As for the crowd, we expect there to be over 94,000 there and records to be broken. It will be electric.

“Dubois is a young man and he’s going in with a guy who’s got impeccable credentials in AJ, an Olympic gold medallist and done everything asked of him up to this point as a professional.

“He’s a two-time world champion and going for his third crack at the title.

“Everyone is excited about the fight due to the styles of the fighters. As they say, styles make fights.

“These guys are both walk-forward fighters who throw big bombs. You’re going to get an exciting fight.”