By Symone Goss, World-Track
On Wednesday the 26-year-old was told she would need to do surgery and could be sidelined for at least six months.
Kluft, who dominated the heptathlon where she won three world championship gold medals in addition to an Olympic gold crown in 2004, was focusing on just doing the long jump at the World Championships next month and she said the injury was the worst setback of her career.
"It obviously feels very heavy," Kluft was quoted as telling Swedish public radio. "This is the worst setback of my sporting career."
At the Beijing Olympic Games last summer, the Swede finished ninth in the women’s long jump and failed to qualify for the final triple jump competition.
Despite the setback, Kluft promised to return.
"I will be back, there’s no question about it." she said.
The world championships in Berlin, Germany run from 15-23 August.