Paula Radcliffe will miss the Commonwealth Games which begin in Melbourne next week after picking up a foot injury at her training base in the United States.
Radcliffe, favourite to win the 10000 metres gold medal, has been training at Albuquerque in New Mexico.
The world marathon champion, who has also been preparing for April's London Marathon at the high altitude venue, developed a bruised foot in January after stepping on a rock.
Radcliffe - although able to comfortably carry on with her marathon build-up - experienced trouble every time she attempted a track session, disrupting her preparations for Melbourne.
The deeply disappointed 32-year-old reluctantly took the decision last night that it would be an unnecessary risk to attempt to chase the 10000m title and add it to the 5000m crown she won in Manchester in 2002.
Gary Lough, her manager and husband, said: "Paula hit a rock when out training and developed a bruised foot and it is taking a long time to settle down.
"In particular it has been causing problems on the track, constantly flaring up and she cannot do proper flat out training sessions.
"It reared up again at the end of January and we feel it would be stupid, too much of an unnecessary risk, to compete in Melbourne."
However, Lough insisted the world marathon record-holder will be well prepared to defend her London Marathon title on April 23.
"The problem is not affecting her marathon preparations," said Lough.
It is the third occasion injury or illness has forced Radcliffe to miss competing at the Games. At the beginning of her senior career, she was absent from the 1994 meeting in Victoria, Canada, recovering from a stress fracture.
Four years later, a virus picked up before the summer's European Championships which saw her underperform in Budapest, then forced her to pull out of the Kuala Lumpur Games.
