British heavyweight David Haye is hopeful his planned world title challenge against Wladimir Klitschko can go ahead at a later date.
Haye was yesterday forced to pull out of his scheduled June 20 bout with the IBF, WBO and IBO champion in Gelsenkirchen due to a back injury sustained in training in Cyprus.
Klitschko initially said he would like to find another opponent for the same date but Haye insists his problem is not serious and could fight after a short postponement.
Manager Adam Booth said: "Unfortunately David has sustained a back injury which means he is unable to continue training for a short period.
"We're heading back to the UK for some aggressive physiotherapy.
"It looks like there will be only a three-week delay from the original fight date, which hopefully means that Wladimir will only postpone the fight, rather than cancel it."
He added that the news was "the most disappointing and devastating that David has ever had to deliver".
The fight was due to take place in front of a sell-out 60,000 crowd at Schalke's Veltins-Arena.
Victory would have made Haye the first British heavyweight world champion since Lennox Lewis retired in 2003.
Haye said: "I'm sorry to disappoint all my fans across the world and I hope that once I have had the sufficient treatment, I will be able to start training again and we can get the fight on as soon as possible.
"I know this is the fight the fans want and I will do everything to make sure it happens."