Valladolid, Spain  - The lowly Vuelta of Castilla and Leon cleared up more issues than expected in the duel between US cycling legend Lance Armstrong and young Spaniard Alberto Contador for leadership of the Astana team.

Armstrong, 37, crashed in the first stage of the race and withdrew with a broken collarbone.

With the injury, he leaves team leadership to his challenger without a great show of force by either. More importantly, Armstrong's training is greatly jeopardized ahead of the Tour de France in July.

"In 17 years as a pro, I have been lucky to avoid one of the most common cycling injuries," Armstrong said, according to a statement released by his team. "The crash has put my upcoming calendar in jeopardy, but the most important thing for me right now is to get back home and rest up and begin my rehab."

Since it was confirmed that he would return to cycling after a three-and-a-half-year retirement, there have been rumours about the chances of a peaceful team coexistence between the winner of a record seven editions of the Tour de France and Contador, who at 26 is the great star of the sport these days.

Astana manager Johan Bruyneel, a good friend of Armstrong's, always said that the road would decide the team's leader. And the road may well have decided, albeit differently than the Belgian intended.

Initially, Astana's heavyweights were only set to race against each other at the Tour de France - the most prestigious race in the world - in July.

That is why it seems ironic that the most decisive moment in Armstrong's return to racing should have happened at a minor race, which was initially only set to free the team of the pressure of fielding the two men together before the Tour.

Armstrong is now likely to be off the road "three to four weeks," according to Vuelta of Castilla and Leon doctor Alberto Gomez. This is an unfortunate blow to the Texan's chances at the Giro d'Italia - the second most prestigious race in cycling - which starts on May 9.

"It's a big, big problem for the Giro," Armstrong told a crowd of reporters as he left hospital in the north-western Spanish city of Valladolid, where he received treatment for his injury.

He returned to racing this season at the Tour Down Under before taking part in the Tour of California and the classic Milan-Sanremo.

Under the original plan, Armstrong was expected to return to the United States following the Vuelta of Castilla and Leon, to train further for the Giro.

But plans are of course changing now.

"I am very, very disappointed," Armstrong admitted. "I feel miserable right now."

He said he needed "a couple of days to relax," and noted that he would make further decisions about his season after consulting with his doctors.

The beneficiary of the latest events is Contador, winner of the 2007 edition of the Tour de France and of the 2008 editions of the Giro and the Vuelta a Espana. The Spaniard had won five consecutive races until he lost the Paris-Nice in the before-last stage, when he suffered a sudden bout of weakness while leading the race.

"It was a good chance to work together in a race," Contador said of his team-mate and rival. "Now I can only cheer him up and wish that he recovers as soon as possible, so he can race in the Giro d'Italia."

A visibly upset Armstrong will need to resort to his well-know fighting spirit to recover from an injury that he had never suffered before.

For now, however, Contador remains Astana's leader on the road. It remains to be seen whether that will change from July 4 at the Tour de France. (dpa)