Jessica Ennis-Hill could face up to 15 weeks on the sidelines with the Achilles injury that forced her to withdraw from the World Championships.
The British athlete's coach Toni Minichiello revealed that a lengthy period of rest is now required to aid her recovery.
"Achilles tendons are awkward and there's a period of rest [involved]," BBC Sport quotes Minichiello as saying. "If we're lucky, then we're looking at a 12 to 15-week recuperation period."
The injury has already caused the Olympic champion to bow out of five events this year, and Minichiello believes that competing in the World Championships in Moscow would have been too much of a risk.
"When she didn't respond well after the London Diamond League, the position was that it didn't make sense and you're probably going to cause her more damage and lose the remaining years of her career to struggling with the injury," he added.
"As a coach I'm not prepared to take that kind of risk so decisions are made and we pulled her at that stage."
The IAAF World Championships take place in the Russian capital between August 10 and 18.
