Tour de France winner Chris Froome to ride Spanish Vuelta
Froome claimed his second Tour de France win last month in a controversial race as the Briton had urine thrown on him and was spat at amid ongoing accusations the 30-year-old was doping.
2013 and 2015 Tour de France champion Froome had already said that he would decide this week about whether or not to take part in the race.
The Vuelta is the third grand tour of the summer after the Giro d’Italia and the Tour.
Thomas had been tipped as a potential leader for Team Sky if Froome decided not to race.
Tour de France victor Chris Froome will be back in the saddle later this month as he tries to add Spain’s Vuelta to his career honours.
Froome joins Nairo Quintana of Colombia and Italian Vincenzo Nibali in a strong Vuelta field.
He has twice finished runner-up in the Vuelta – in 2011 and last year, when he lost out to Alberto Contador.
The final Grand Tour of the year begins with a team time-trial in Puerto Banus on August 22 and runs for three weeks before finishing in Madrid on September 13.