CA Osasuna has officially announced its intention to lodge a formal complaint with the Spanish Football Federation's (RFEF) Competition Committee, accusing FC Barcelona of fielding an ineligible player, Iñigo Martínez, during their 3-0 defeat on Thursday in LaLiga EA Sports Matchday 27.

The controversy centers on Iñigo Martínez’s inclusion in Barça’s squad just five days after being withdrawn from Spain’s national team due to injury. Osasuna claims this violates Article 5 of Annex 1 of the FIFA Regulations on the Status and Transfer of Players, which states that a player who misses international duty due to medical reasons cannot participate in club matches during the five-day period following the end of the international window.

According to the statement released by Osasuna, the defender was ruled out of Spain’s squad on March 17 due to parameniscitis in his right knee, and did not report to the national team to undergo evaluation by the medical staff—something required by FIFA for the suspension to be lifted.

Osasuna defends its position

In its official release, the Navarrese club explained that the decision to file the complaint is made “in defense of its rights, the fairness of the competition, and the equality of all participants.” The club emphasized that similar cases—such as those involving Marc Casadó or Bryan Zaragoza—saw players at least report to their national teams for assessment.

By contrast, Martínez was excluded without appearing, which Osasuna claims should have rendered him ineligible to play in the match against them.

What the rule intends and what’s at stake

FIFA’s five-day rule is designed to protect national team interests and prevent clubs from benefiting from players who skip international duty. Osasuna insists that no exceptional circumstances apply in this case and has called on LaLiga authorities to enforce the rule strictly.

The Competition Committee will now evaluate the claim. If the ruling goes in Osasuna's favor, Barcelona could be sanctioned with a 0-3 forfeit loss, awarding Osasuna the three points.

Should the complaint succeed, the decision could impact both ends of the league table—from the fight for European places to the relegation battle. It would also set a precedent in the application of FIFA's international window rules within domestic competitions, especially in tightly contested seasons like this one.