Anthony Joshua has never worked harder in a training camp, but his promoter Eddie Hearn admits he is ‘nervous’ ahead of the heavyweight's crucial April 1 return.

Two-time world champion Joshua is looking to bounce back from back-to-back defeats to Oleksandr Usyk when he takes on 21-1 Jermaine Franklin at the O2 Arena, London next month.

It will be Joshua’s first fight since linking up with Derrick James and Hearn believes the move has driven the Londoner to his most punishing training camp in 10 years as a professional.

But Joshua’s career is on the line against Franklin, whose last fight was a controversial majority decision defeat to Dillian Whyte in November, a fight many thought the Michigan man won.

Hearn, who visited Joshua at his Texas training camp this week, said: “AJ’s looking good but I’m nervous.

“People are saying this is a straightforward fight for Anthony Joshua but it’s not at all.

“Let’s look at the facts, he’s coming off two defeats to the pound-for-pound No.1 Oleksandr Usyk but you saw the emotional side to AJ in the last performance and after the fight.

“Franklin is full of confidence coming off the Dillian Whyte fight and he looks all of a sudden about 20lbs lighter as well.

“This is a big moment for Anthony Joshua’s career, people are talking about fights against Deontay Wilder, Whyte, Fury but he has to win on April 1.

“Franklin is a good fighter who is going to come well equipped but AJ has worked himself hard out there in humble, humble surroundings.

“This is just him, Derrick James and Erroll Spence. Just hard work. I think this is the hardest he’s ever worked in camp and I really hope that he can produce the performance that he deserves on April 1 because I believe he’s still in his prime.

“But he has to beat Jermaine Franklin.”