Anthony Joshua
Joshua is to return to the ring in April Getty

Anthony Joshua's world title shot against IBF heavyweight champion Charles Martin has come "two or three fights too early", according to promoter Eddie Hearn. The Olympic gold medallist is set for his first world championship fight in his 16th professional bout and Hearn admitted he is surprised by the rate of Joshua's progress.

The Brit has won all of his professional fights by knockout and is widely regarded as one of the most exciting prospects in the sport. But Hearn said he did not originally plan for Joshua to challenge for the heavyweight championship at this stage in his career.

"It's come two or three fights too early and we didn't expect to fight for the word title now but this is the situation," Hearn said of Joshua, who is set to face Martin at London's O2 Arena on 9 April. "We probably would not have looked to fight a 6ft 5in, awkward southpaw like him, so it is a risk. He can punch, Martin, but Joshua is the favourite."

Hearn revealed Joshua had no hesitation in accepting the fight against the unbeaten American. "It was a difficult decision and I just said to Anthony's people, make your decision on can you beat Charles Martin? If you think you can, then you have to take this fight, and Joshua was in like that!" he said, according to The Mirror.

"As soon as Martin said he would fight him, Joshua asked if I could get him. The carrot for Joshua is, win this and you become world heavyweight champion."

Hearn also said if Joshua is successful in his first shot at a world title, he will look at the same calibre of opponents for his first defence in the summer. "People said if he wins this, then he will become world champion and you won't be able to step back," he said.

"But the people we would be looking at for voluntary defences are the same people you'd be looking at to fight on April 9 – Bryant Jennings, Bermane Stiverne, Malik Scott. Malik Scott is in the top 15 in the rankings, Bryant Jennings, Stiverne, they're all ranked fighters. So any of them would do for a first defence and that would be in June."