Chile and Peru have appealed to the Court of Arbitration for Sport against Fifa rulings on the eligibility of Ecuador’s Byron Castillo.
The Peruvian Football Federation (FPF) has asked for Ecuador be excluded from the World Cup and be replaced by Peru.
Chile’s football association has asked Cas to rule Castillo as ineligible for the qualifying games he played in and declare those matches as forfeited.
The 23-year-old played in eight of Ecuador’s 18 World Cup qualifiers.
In June, Fifa ruled that Castillo is eligible after the Football Federation of Chile (FFC) filed a complaint claiming Castillo is Colombian and had falsified his age.
Earlier this month, the football associations of Chile and Peru lodged appeals but Fifa’s appeals committee said the right-back does qualify for Ecuador.
Ecuador finished fourth in Conmebol qualifying and claimed an automatic place at the Qatar World Cup ahead of Peru.
If Ecuador should forfeit the eight games Castillo played in, and their opponents be awarded three points for each of them, that would see Chile, who finished seventh, leapfrog sixth-placed Colombia and Peru into the fourth automatic spot.
Both the FPF and the Chilean Football Association (FFCH) have asked Cas to issue its final ruling on or before 10 November, 10 days before the start of the World Cup.
A statement by the Court said: “The Cas arbitrations have commenced and are at an early stage. A procedural calendar is in preparation.”