Former Tour de France winner Andy Schleck has retired from cycling at the age of 29 because of a knee injury.
The Trek Factory Racing rider has failed to recover from an injury sustained in a crash in London on the third stage of the 2014 Tour de France.
"I would have liked to keep on fighting but my knee doesn't allow it," he said.
Schleck was awarded the 2010 Tour de France title in 2012 after Spaniard Albert Contador was stripped of the yellow jersey for failing a drugs test.
The Luxembourger finished second in the 2009 and 2011 Tours, and won the 2009 Liege-Bastogne-Liege one-day classic after a gutsy breakaway.
Schleck, who crashed close to the Olympic Park in London on the last of the Tour de France's three days in England this year, added: "Since my crash in the UK there has hardly been any progress.
"While the ligaments have healed, the damaged cartilage is another story. I have been working hard on rehabbing the knee but came to the hard realisation that at the risk of irreversibly injuring it, this is the best course of action."