LIMA -- Peru captain Paolo Guerrero appealed to Switzerland's highest court on Friday to overturn a doping ban that has ruled him out of the World Cup in Russia.

Backed by the Peruvian Football Federation (FFP), Guerrero lodged an appeal with the Swiss Federal Tribunal on Friday after the Court of Arbitration for Sport (CAS) last week extended his six-month suspension to 14 months.

The CAS decision means the 34-year-old Flamengo striker will miss Peru's first World Cup since 1982, which begins on June 14.

"He is the unquestioned captain of the Peruvian team and a national emblem of hope for the whole country," FPF president Edwin Oviedo said in a sworn statement, which the association published on social media.

"I beg with all my heart to take into account not just Paolo's interest but that of the entire nation."

Guerrero was given a 12-month ban last December after testing positive for the cocaine metabolite benzoylecgonine following Peru's World Cup qualifier against Argentina in Buenos Aires on October 5.

The penalty, backdated to November, was halved by FIFA's appeal committee less than two weeks later.

Guerrero, who is Peru's all-time leading scorer with 32 goals from 83 matches, has maintained his innocence and says the substance was unwittingly consumed in contaminated tea.

The case was referred to the CAS after a challenge by the World Anti-Doping Agency.

Earlier this week the captains of Peru's World Cup Group C rivals - Australia, France, and Denmark - urged FIFA to reconsider the ban. In a letter sent by players union FIFPro, Mile Jedinak, Hugo Lloris and Simon Kjaer said the punishment did not fit the crime and called for the ban to be temporarily lifted.

Guerrero on Tuesday met FIFA president Gianni Infantino, who expressed a "deep understanding" of the forward's plight but indicated he could not change the decision.