The 34-year-old was supported by President of the Peruvian Football Federation, Edwin Oviedo, who sent a written statement to the Federal Supreme Court, which was published on the official website of the federation.

"He is a true Peru captain, a national symbol of the country's hope. I plead with you to take into consideration, not only Paolo's interests, but the country's interests as well," the statement said.

In December 2017, FIFA's Disciplinary Committee banned Guerrero for one year, with the FIFA Appeal Committee later reducing the sanction to six months after the player said that the substance was accidentally consumed in tea contaminated with coca leaf.

The footballer and the World Anti-Doping Agency (WADA) both later appealed to CAS with Guerrero hoping for the ban to be fully lifted and WADA asking for the penalty to be extended. CAS agreed to extend the ban to 14 months, meaning Guerrero would only be able to return to the pitch in 2019.

CAS is situated in Switzerland and is constituted under Swiss law, meaning that its decisions can be appealed to the country's Federal Supreme Court.

Guerrero is Peru's all-time top goalscorer, having netted 33 goals in 87 matches since his international debut in 2004.

Peru, who will play at their first FIFA World Cup since 1982, will face France, Denmark and Australia in Group C at the tournament in Russia, which will be held from June 14 to July 15.