Paris (AFP) – Italy's Vincenzo Nibali, who was forced out of the Tour de France after a crash on the 12th stage to Alpe d'Huez, underwent surgery on his injured back in Milan, his Bahrain team said on Tuesday.

The 2014 Tour champion will be released from hospital on Wednesday and will be able to return to training in a few days, starting on a stationary bike before heading back out on the road.

The Italian champion is planning to race the Vuelta a España in preparation for the World Championships.

Nibali fractured a vertebra on July 19 after his bike got tangled up with a bag or camera strap, sending the cyclist crashing to the ground as he rode through a plume of smoke on the crowded climb.

He finished the stage seventh and was fourth overall, two minutes and 37 seconds behind eventual winner Geraint Thomas, but was ruled out of the rest of the race.

The 33-year-old is one of just seven riders to have won all three Grand Tours. He also won this year's Milan-San Remo, one of cycling's five prestigious one-day 'monuments'.