Lance Armstrong believes he will be fit to race in May's Giro d'Italia despite having an operation today on his collarbone which has broken into "multiple pieces".

The seven-time Tour de France winner crashed on stage one of the Vuelta a Castilla y Leon in Spain and will undergo surgery in the United States to insert a metal plate to strengthen the affected area.

Although the damage is worse than first feared, the American remains confident about his recovery. "The scan showed the clavicle in quite a few more pieces than we originally thought," said Armstrong.

"There will definitely be a plate placed on the top of the clavicle so the surgeon can anatomically put all this stuff back together. Obviously the Giro is on people's minds and that's about five weeks away.

"I think the Giro is still very do-able but this is definitely a setback. It's the biggest setback I've had in cycling."

Standard recovery for this injury is four to six weeks, leaving the American with no room for setbacks in his rehabilitation with the Giro due to begin on 9 May.

He added: "It's a very common cycling injury. You hear of guys who race two weeks later, you hear of guys who race two months later."