Anthony Joshua's long-awaited US debut is surrounded by uncertainty after opponent Jarrell Miller failed a drugs test.
Joshua is still set to put his IBF, WBA and WBO heavyweight belts on the line at Madison Square Garden on June 1.
But is is uncertain who he will face with Miller unlikely to be granted a license after irregularities showed up in his VADA drugs test.
Joshua is continuing to prepare for his June 1 bout with Eddie Hearn and his team at Matchroom Boxing working hard behind the scenes to source an alternative opponent.
And Hearn has opened up on Joshua's response to the shock news that broke early on Wednesday morning regarding Miller.
Manuel Charr approached to fight Anthony Joshua after Jarrell Miller's failed drug test
Speaking to IFL TV , Hearn said: "He (Joshua) was the first person I called.
"I just said 'mate, I've got some terrible news', he said 'what' and I said 'Miller's failed a drugs test'.
"He just replied 'You're joking?', I said 'no, can't believe it'.
"He didn't even sound that surprised to be honest with you, he just said 'OK, who's next?'
Dillian Whyte reacts to possibility of fighting Anthony Joshua
"I said 'who'd you want?' and he just said 'absolutely anyone, no problem'.
"I text him this morning telling him to stay focused and he's just done six miles on the road. He's just an absolute pro.
"I don't think he's over the moon with Jarrell Miller, especially everything that's been said in the build-up."
Anthony Joshua's potential opponents if Jarrell Miller is banned for failed drugs test
A number of fighters are being considered as potential replacements for Miller - but Hearn admitted Luis Ortiz is top of the wish list for both him and Joshua.
"That was the first name he gave me last night," he revealed.
