PORRENTRUY, Switzerland (AP) -- Defending Olympic champion Samuel Sanchez withdrew from the Tour de France after a crash during the eighth stage in which he broke his right hand and injured his left shoulder. He could miss the London Games.

The crash happened 35-miles into the stage that took the riders into the Swiss mountains on Sunday.

Sanchez fell on his side before two other riders landed on him. He sat on the ground in tears, clutching his left shoulder and arm as medical teams tended to him. He could not get back on a bike and was put on a stretcher and taken by ambulance to a nearby hospital in Montbeliard.

"We suspect a dislocated or a broken shoulder," Tour doctor Florence Pommerie. "He also lost consciousness for a couple of seconds, probably because of the pain."

Sanchez underwent X-rays that confirmed he broke his hand but could not reveal the full extent of his shoulder injury. Sanchez will head back to Spain on Monday for a scan, Euskaltel-Euskadi spokesman Jesus Aizkorbe told The Associated Press.

"The most important thing is my health," Sanchez said. "I want to know how serious is my injury in order to start a recovery program as soon as possible. Today I cried on the road because it's hard to leave the Tour so early, before the two time-trials, the Alps and the Pyrenees."

Alejandro Valverde of Spain, one of the two riders who fell on Sanchez, cut his shin in the crash, Pommerie said.

Sanchez had started the day in 12th position, 2 minutes and 2 seconds behind Tour leader Bradley Wiggins. The 98-mile ride on Sunday from Belfort to the Swiss town of Porrentruy features seven climbs.

Crashes have marred the first week of the Tour and Sanchez became the 20th rider to drop out of the three-week race. Sanchez won a Tour stage last year on his way to winning the best climber's polka-dot jersey.

He was set to defend his Olympic title in the road race July 28. It's not clear if Sanchez will recover from his injuries in time to compete.

"It will be up to the national coach to decide," Aizkorbe said, referring to London. "We'll speak with him as soon as possible."

SI Apps
We've Got Apps Too
Get expert analysis, unrivaled access, and the award-winning storytelling only SI can provide - from Peter King, Tom Verducci, Lee Jenkins, Seth Davis, and more - delivered straight to you, along with up-to-the-minute news and live scores.