The captains of Australia, Denmark and France have asked Fifa to lift the ban on Paolo Guerrero – the skipper of group rivals Peru – so he can play at this summer’s World Cup in Russia.

Guerrero, who tested positive for cocaine after a qualifier against Argentina on 6 October, is serving a 14 month ban. The Peru forward continues to plead his innocence, saying the positive result was caused by coca residue in a cup of tea he used to calm his stomach before an important match.

The Flamengo striker was initially banned for 12 months but the ban was reduced to six months by FIFA’s appeal committee in December, allowing the 34-year-old forward to play again this month for the Brazilian club and prepare for the World Cup.

But the Swiss-based CAS, on appeal from the World Anti-Doping Agency, last week extended the suspension to 14 months, effectively sidelining Guerrero for Peru’s first World Cup tournament in 36 years.

In a letter to football’s world governing body, it asks for a “temporary interruption” to his suspension so he can appear for Peru at their first World Cup in 36 years.

Signed by Australia’s Mile Jedinak, Denmark’s Simon Kjaer and France’s Hugo Lloris, the document – released by world players’ union FIFPro – asks FIFA for “compassion” and an “equitable and rightful solution” which would allow Guerrero to reach the “pinnacle” of his career.

Hope was in the air in Lima on Sunday, when thousands marched a little over half a mile from a large park in central Lima to the national stadium. The fans had been encouraged by news media reports that Guerrero and the head of Peru’s soccer federation were planning to fly to Switzerland for a meeting with FIFA President Gianni Infantino.

Guerrero, in a farewell video posted online before he boarded a plane for Switzerland, did his best to boost hopes that the trip would succeed.

“A sign of hope, an opportunity has been presented,” he said. “I hope to return from Switzerland with good news.”

Peru kick off their World Cup campaign on 16 June against Denmark in Group C.