Britain's Rowan Cheshire has been ruled out of competing at the Sochi Olympics following a fall in training on Sunday.
The 18-year-old halfpipe skier suffered concussion as a result of the fall and spent the night in hospital under observation.
In a statement, Team GB said the decision was made by Cheshire, Team GB chief medical officer Niall Elliott and GB freestyle head coach Pat Sharples that Cheshire needed more time to recover.
Cheshire was due to compete on Thursday but guidelines from the sport's governing body FIS suggest a minimum of six days' rest following a concussion.
Elliott said: "With a concussion injury there needs to be a rest period followed by a graduated return to play phase. The time scale is unfortunately too tight for Rowan."
Sharples added: "We are relieved that Rowan is on the mend but naturally upset for her that she won't be able to compete in Sochi.
"She is only 18 years old, however, and has a bright future ahead of her. I have no doubt she will be back in four years' time more determined than ever."
Cheshire was considered a good medal prospect for Great Britain after winning her first World Cup title in Calgary last month.
But the extent of her injuries were evident in a photograph she posted of herself on her Twitter account on Monday morning, displaying visible cuts and bruising and with the message: "Wasn't the best day yesterday, still don't remember much! Thanks everyone for the lovely messages."
Cheshire is not the only athlete to be forced out of the Games following an accident at the Rosa Khutor Extreme Park.
In the most serious incident, Russian ski cross athlete Maria Komissarova sustained a broken and dislocated spine after a training accident, and underwent a six-and-a-half hour operation in Krasnaya Polyanskaya Hospital before being transferred to Munich for follow-up treatment.
Snowboard cross competitors Helene Olafsen and Jacqueline Hernandez were both stretchered off the course after falling heavily, while Swiss aerials skier Christopher Lambert sustained a dislocated elbow after a fall in training.