Joe Calzaghe has withdrawn from his IBF world light-heavyweight title challenge against Glen Johnson next Saturday.
Promoter Frank Warren said the undefeated Welshman, who was stepping up to 175lb for the first time after reigning as WBO world super-middleweight champion for nearly seven years, sustained a serious back injury in a sparring session last week.
Since then, Calzaghe has been receiving physiotherapy treatment in London which he has not responded to and the decision was made for him to withdraw from the bout at Manchester's MEN Arena.
