British super-middleweight champion George Groves has been forced to pull out of his title defence against Kenny Anderson because of a back injury.
The fight, scheduled to top the bill on Friday at Wembley Arena, will be rearranged by promoter Frank Warren.
"I'm gutted and hoping for a quick recovery," Groves later tweeted.
"I suffered a back injury sparring with Eamonn O'Kane and haven't trained properly since," the Londoner elaborated.
"I failed a fitness test today and decided to withdraw.
"Every fighter knows when you get injured you don't just give up. You give yourself every chance to recover and fight. I didn't recover."
Anderson, who at 29 has won his last three fights, has been angered by the late withdrawal.
"I am gutted," the Edinburgh-based boxer told website Boxing Scene.
"I don't believe in my heart that he is injured. That's the feeling I've got. I don't think they wanted to have this fight.
"George has heard about how I'm doing, about the condition that I'm in, and he's bottled it."