Cape Verde are to appeal to the Court of Arbitration for Sport for the right to replace Tunisia in the World Cup playoffs, despite the first leg of Tunisia's playoff match already having taken place.
The court said Cape Verde's FA had appealed against a FIFA ruling to award Tunisia a 3-0 victory in a decisive group match in September. Cape Verde won the match 2-0, but were penalised for fielding an ineligible player.
That meant Tunisia qualified for the playoffs, where they drew 0-0 at home to Cameroon earlier this month.
The court said the appeal was for that result to be wiped out, the second leg cancelled and Cape Verde readmitted to the competition to play the two-legged tie against Cameroon.
FIFA, which fined Cape Verde and upheld the decision to award the match against them at an appeals committee hearing this month, has refused to allow the court process to be fast-tracked.
A statement from the court said: "A regular CAS arbitration has been initiated, and no procedural calendar has been fixed yet."
Cape Verde were punished after Tunisia complained that defender Fernando Varela was ineligible to play because he had not completed a four-match ban for being sent off against Equatorial Guinea in March.
That match was forfeited by Equatorial Guinea, also over an ineligible player, but FIFA rules mean red and yellow cards stay on the record.