Kell Brook has withdrawn from his scheduled clash with Brandon Cook due to an ankle injury, promoter Eddie Hearn has confirmed.
There has been speculation for the last few weeks that the Sheffield fighter would not be competing as planned on July 28 at London's O2 Arena.
But, in an interview with IFLTV, Hearn has finally confirmed the rumours, explaining he wanted to have a replacement fight in place before announcing Brook had pulled out.
"A lot of the time you want to announce a withdrawal with the replacement, that is standard practice and sometimes there is a crossover," Hearn said.
"With the Kell Brook stuff, he has had a foot injury, an ankle injury that he picked up two weeks ago.
"I spoke to Dominic [Ingle, trainer] and it was a case of we think he'll be okay.
"But at the end of last week it was decided that he could not make the fight."
Hearn said he had hoped to announce a fight between Commonwealth heavyweight champion Joe Joyce and Nick Webb to replace Brook v Cook, but the final contracts had yet to be signed.
"I told everyone when Brook was injured two weeks ago and said we're monitoring him and hopefully he'll be okay," he said.
"I didn't have to tell you that, but it's the truth.
"I just hoped last week that I could announce the Joe Joyce fight and I'm still chasing [managers] Hayemaker up on that."
Matchroom Boxing chief Hearn says Brook will not be out of action for long and now faces a choice of competing in early Autumn or waiting to see if the blockbuster clash with Amir Khan can finally be made for December.
"Kell is not going to be out for a long time," Hearn said.
"But it's just a case now of does Kell now wait for the December fight against Khan or does he have that fight in September in the mean time because it's starting to close the gap.
"He could go on the Anthony Joshua card [September 22] for example."