Contador quit the Tour de France, which he had been bidding to win for a third time, after suffering a fractured shinbone on the tough 10th stage.
"Bad day today. The healing of the wound is getting complicated... Goodbye to the Vuelta," Contador wrote in Spanish and English on Twitter.
Bad day,the wound healing gets complicated,I've no date to take the bike.Goodbye to the Vuelta.— Alberto Contador (@albertocontador) July 23, 2014
The 31-year-old crashed badly on a descent during the mountainous stage from Mulhouse to La Planche des Belles Filles.
He did not need surgery on his fractured tibia, and in a second tweet thanked doctors in Madrid's Cemtro Clinic for their treatment.
Quiero expresar mi agradecimiento a los doctores de la Clinica Cemtro por la gran atencion que estoy recibiendo.— Alberto Contador (@albertocontador) July 23, 2014
The Saxo-Tinkoff rider won the Vuelta in 2008 and 2012. This year's race runs from August 23 to September 14.