David Haye has postponed next week's fight with Tyson Fury after suffering a deep cut in sparring at his training camp.
The cut above his left eyebrow needed six stitches, which have to stay in place for five to seven days.
"Gutted isn't even the word. Mentally, I'm on the floor at the moment," said the former WBA heavyweight champion.
Haye is awaiting further medical tests before setting a new date for the Manchester bout.
The 32-year-old also pulled out of what should have been his previous fight, against Manuel Charr on 29 June, because of a hand injury sustained in training.
Fury reacted to the news by telling followers on Twitter: "Sorry for everyone who bought tickets and hotels. Haye's excuses are boring. He doesn't want to fight me!"
Fury's uncle and trainer, Peter, also vented his anger at the postponement and rubbished the prospect of the pair meeting in the future.
He said: "We move on from Haye now and look to better things. This has put a bad taste in our mouths so we're moving on and the fight will not be rearranged on our side."
Hayemaker Promotions said that "after being properly assessed", Haye was left with no choice but to postpone the Fury fight.
"I'm devastated. I know injuries and cuts are part and parcel of our sport, but this doesn't change the feeling of disappointment and sadness I'm experiencing right now," Haye added.
"Even when everything seems to be right on track, sometimes life throws you a curveball. I will somehow have to try and make the best of this horrible situation. But, right now, I'm in bits about what has happened."
Three days ago Haye had taunted 24-year-old Fury ahead of the bout by insisting his sparring partners would beat his fellow Briton.
Fury would have put his unbeaten record on the line at Manchester Arena with Haye being the bookmakers' favourite, having lost only two of his 28 paid fights, most recently against Wladimir Klitschko in a world heavyweight unification bout in 2011.
Fury, who beat American Steve Cunningham in April to move to 21 fights unbeaten, turned down a bout against Bulgarian Kubrat Pulev that could have earned him an IBF world title shot against Klitschko in order to fight Haye.