Nairo Quintana announced that he will not participate in the upcoming Vuelta a España following Wednesday's news that he was disqualified from the Tour de France due to two positive tramadol tests.

The Colombian, who was scheduled to lead Arkea Samsic in the race, announced Thursday morning that he would not participate, despite UCI rules allowing him to do so.

He said he would fight his disqualification from the Tour de France in the Court of Arbitration for Sport in a trial to validate the UCI's Tramadol ban (the drug is not prohibited under WADA rules).

"I announce that I will not participate in the Vuelta in order to argue my reasons in the Court of Arbitration for Sport (CAS)," Quintana said in a statement. He will "return to the race calendar at the end of the season.

Quintana's sixth-place finish at Arcare Samsic was his best GC finish at the Tour since the 2016 edition. He tested positive for opioid painkillers in La Planche des Belles Fils and Col de Granon, finishing second in the latter mountain stage.

Following the news of his disqualification, the 32-year-old issued negative comments Wednesday night. However, he seemed to reverse this decision overnight, stating that he would compete in the Vuelta.

"I was surprised to learn today that the UCI announced a violation for tramadol use. I had no knowledge of the use of this drug and I deny having used it in my career," Quintana said.

"Together with my legal team, I am exhausting all procedures for my defense. I also want to confirm that I will stay in the Vuelta, ride my bike, and do everything I can for my team, my country, and my supporters."

The UCI ruling gave Quintana 10 days to appeal to CAS. It is unclear when Quintana will be able to return to racing.