Dereck Chisora has been forced to withdraw from Saturday's fight with Tyson Fury in Manchester.
The promoters announced that heavyweight Chisora had fractured his hand in training and would not be able to defend his European title against Fury this weekend. The vacant British heavyweight crown was also up for grabs.
Chisora injured his hand during a sparring session which means their clash will have to be rescheduled on a date yet to be decided.
In a statement from the promoters, Chisora said: "I can't tell you how disappointed I am to have to pull out of the fight against Fury.
“But it is on the advice of my specialist that I have to do this.
"I'm sorry for the fans who will get to miss this great fight between me and Tyson but once my hand is healed and I'm given the all-clear to train and punch again, I'll be working on the new date for the fight."
Chisora, who was keen to avenge his defeat to Fury on a unanimous points decision three years ago, added: "I was in fantastic shape and had a great training camp, probably the best so far in my career and was looking forward to getting revenge.”
Promoter Frank Warren added: "Everybody involved in the fight worked hard to get it on and, for this to happen on the final week, is a big disappointment to everyone.
"There's no way that Dereck could fight with his hand fractured and there's no way I would let him get into the ring and fight with an injury like that.
"Obviously, you've got to feel for Tyson who, through no fault of his own, has been hit hard by this postponement after all the training he has put in.
"It's a big heavyweight fight with a lot at stake for both fighters and we're working hard to get a new date confirmed."
However, the show will still go ahead with Billy Joe Saunders taking on Emanuele Blandamura for the vacant European middleweight title.