Rosen's best result was sixth in a World Cup race
Britain's top luge athlete faces a race to be fit for the Winter Olympics after crashing during a training run.
Adam Rosen dislocated his hip in the high-speed accident on the track in Whistler, Canada, which will be used during the Games next February.
Performance director Richard Simmons told BBC Sport it was a serious blow to the 25-year-old's Olympic preparations.
"The crash and resultant injury is a serious setback but AJ is determined to bounce back," Simmons said.
Rosen finished 16th in the 2006 Winter Olympics and recorded the best result for a British slider when he came sixth in a World Cup race in Calgary in February 2009, albeit on a sled borrowed from the better-funded Canadian team.
Rosen, who is based in North America, has been critical of his inferior equipment and lack of official funding, which he claims has hampered his Olympic chances.
However, a positive training arrangement with the Canadian Luge Association allowed him four valuable weeks of access to the track at Whistler Sliding Centre in the build-up to the 2010 Games.
Hence the accident, on his third day of training, makes his injury all the more frustrating.
Simmons added: "Once the bruising subsides and he regains feeling in his foot, he will undergo a series of scans to ascertain the actual extent of the injury.
"A rehabilitation programme will be created to get AJ back to race fitness.
"AJ is now involved in a race against time to be fit for the season but the focus is still on performing in the Olympic Games in February."
Britain is aiming to send about 50 athletes across six sports to the Winter Olympics, which will be held between 12-26 February.