Tunisia's attempt to have Toulouse midfielder Nabil Taider at the World Cup finals has been turned down by Fifa.
Taider is over Fifa's age limit
The Tunisian Football Federation had applied for a change of footballing nationality for the French-born striker, who qualifies for Tunisian citizenship through his parents.
Fifa ruled that Taider was ineligible for the nationality change because he was over the age limit of 21.
The 22-year-old Taider is in his third season of French Ligue 1 football with Toulouse.
Tunisia are drawn against Saudi Arabia, Spain and Ukraine at the World Cup finals in Germany in June.