Contador, who announced on Monday this year's Vuelta would be his last professional race, will be bidding for a fourth title after his triumphs in 2008, 2012 and 2014. "It's a decision that I have thought very well and I don't think there is a better farewell than in the home race and in my country".
Contador is a three-time victor of the Vuelta, sealing victories in 2008, 2012 and 2014, while he was also Giro champion in 2008 and 2015.
Second only to five-time Tour victor Miguel Indurain in Spanish cycling lore, the 34-year-old Contador has been one of the sport's top riders for the last decade in a contentious career.
Leading generalist of his generation, won three times on the stages of the Tour de France, five times he took cuts on the home tour, and in 2009 became the champion of Spain in race with separate start.
The Spaniard, one of six riders to have won all three Grand Tours in a 14-year professional career marred by a doping ban, made his announcement on Instagram yesterday.
"I'm sure they will be three wonderful weeks".
Contador was stripped of victory at the 2010 Tour de France and the 2011 Giro d'Italia, after he was found to have tested positive for the banned substance clenbuterol at the former.
While the Spanish cyclist initially meant to retire in 2016, he joined Trek-Segafredo for one past year in the saddle, finishing ninth in the 2017 Tour de France.
Contador is also one of just six riders to have won each of the Grand Tours - the Tour de France, Vuelta and Giro d'Italia.
Contador will have many strong competitors to beat-including Chris Froome, Fabio Aru, Vincenzo Nibali, and Romain Bardet-if he intends to snag one last Grand Tour victory before retirement.