England's Katarina Johnson-Thompson will miss the 2014 Commonwealth Games in Glasgow because of a foot injury.
The 21-year-old was told to withdraw on medical advice after being diagnosed with a "stress reaction".
She said: "The Commonwealths was a key target for me this year. I was feeling so good in my preparation up until this week so this is a real blow."
Johnson-Thompson posted the highest heptathlon score of the year with a personal-best 6,682 points last month.
|Britain's all-time leading heptathletes|
|Jessica Ennis-Hill - 6,955 points (2012)|
|Denise Lewis - 6,831 points (2000)|
|Katarina Johnson-Thompson - 6,682 points (2014)|
|Judy Simpson - 6,623 points (1986)|
Her performance at the prestigious Hypo-Meeting in Gotzis made her one of the favourites to win gold in Glasgow.
The Liverpudlian said: "All the advice is telling me that I risk long-term damage if I compete in a heptathlon in just over a week's time, and I have to take that advice for the sake of my career."
Johnson-Thompson had been competing in the long jump, one of the seven heptathlon disciplines, in the run-up to the Commonwealth Games, which open on Wednesday.
"I really hope to be able to compete in the long jump at the European Championships next month, but it doesn't take away how gutted I am that I won't be at the Commonwealths," Johnson-Thompson said.
Ennis-Hill sent a message to Johnson-Thompson after news broke about her withdrawal. "So sorry to hear about your injury," she said. "I know exactly how you must be feeling. But have no doubt you will be back even stronger! This injury is just part of your journey & I know you've got such an exciting future! Xx"
Commonwealth champion Louise Hazel came out of retirement in an attempt to defend her title but, after a flare-up of ulcerative colitis in June, will work for BBC Radio 5 live at the Games instead.
The 28-year-old shared a room with Johnson-Thompson during the 2012 Olympics and suggested her compatriot's recent exertions in the long jump may have contributed to her injury.
"I just question whether that was perhaps a little bit much for her ahead of the championships," Hazel said.
|Stars at Commonwealth Games||Missing in action|
|Usain Bolt - Jamaica's six-time Olympic champion and 100m world record holder will run the 4x100m||Yohan Blake - Jamaican 100m and 200m Olympic silver medallist will not compete|
|Bradley Wiggins - Four-time Olympic gold medallist will cycle on the track for England||Mark Cavendish- The Isle of Man cyclist damaged his shoulder in the Tour de France|
|Mo Farah - Double Olympic champion will race the 5,000m and 10,000m for England||Jessica Ennis-Hill- England's Olympic heptathlon champion has just given birth|
|Sally Pearson- Australia's Olympic champion will defend her Commonwealth title in the 100m hurdles||Becky James - Welsh sprint and keirin cycling world champion has a knee injury|
|David Rudisha - Kenyan world record holder and Olympic champion goes in the 800m||Saina Nehwal - India's Commonwealth badminton champion is out injured|