World heavyweight champion Vitali Klitschko has again had to postpone his World Boxing Council (WBC) title defence against Hasim Rahman after injuring his knee while sparring.
Klitschko, who twice pulled out of fights with Rahman earlier this year because of thigh and back problems, suffered the injury to his right knee on Thursday in Los Angeles.
After taking medical advice on Friday and Saturday, the Ukrainian decided he could not go ahead with the fight against American Rahman in Las Vegas next weekend.
"I had a special bandage fitted to my knee but sparring was still difficult," Klitschko said on his website.
"We decided the trauma I received would not allow me to enter the ring on November 12."
The 34-year-old Klitschko, who was set to pick up $7.8 million for the fight, said it was too early to say when he might be able to box again.
