Kurt-Asle Arvesen has fallen during stage two of the Tour of Qatar and has suffered a broken collarbone, forcing him to withdraw from the race.
Arvesen was part of Sunday's winning Team Sky line-up that convincingly clinched the race's opening team time trial.
The Norwegian fell within stage two's neutralised zone, although it is unclear exactly what caused the accident.
"It was really an absurd kind of accident because it happened before the race proper had started," Arvesen told the Team Sky website.
"We were basically just getting ready to start racing when I let a guy go past me but it then got a bit narrow and I lost control of the bike and crashed to the ground."
"It's really unfortunate to break your collarbone at any time but especially now as I was just getting ready to start my year."
Arvesen was forced to withdraw from the Tour de France last year after crashing and fracturing his collarbone - a break which later required surgery.
Arvesen's Sky team-mate and compatriot Edvald Boasson Hagen currently leads the six-stage Tour of Qatar, which concludes on Friday, February 12.
Related links
Team Sky win opening stage in Qatar to put Boasson Hagen in yellow
Kurt-Asle Arvesen: Rider Profile
Tour of Qatar 2010: Preview and coverage index
