Italy's former pink jersey wearer Alessandro De Marchi broke his collarbone and six ribs among other injuries after crashing on the 12th stage of the Giro d'Italia on Thursday.
De Marchi of the Israel Start-Up Nation team crashed 20km into the stage between Siena in Tuscany and Bagno di Romagna and was taken away in an ambulance.
He did not lose consciousness, his team said.
"Dema was taken to hospital and was diagnosed with a broken right collarbone and six broken ribs," his team later confirmed.
"He also broke his first and second thoracic vertebra. He did not suffer any head injury, but does have to stay in the hospital for at least one night."
The Italian wore the pink jersey for two days in the first week of racing but had dropped to 62nd overall.
Spaniard Marc Soler of Movistar also crashed out on Thursday.
Movistar's Soler, who was 11th overall, fell shortly after the start of the stage and was forced to stop after 50km with a sore back.
Two other riders, De Marchi's British teammate Alex Dowsett, and Swiss Gino Maeder of Bahrain also opted to pull out before going through the Tuscan city of Florence, 62km into the race.
Maeder won the sixth stage at Ascoli Piceno, and his and Dowsett's exit leaves their respective teams with five riders.