Ligue 1 outfit Nice have revealed that they are to refer the Yannick Djalo case to the Court of Arbitration for Sport.
The 25-year-old agreed a move to France on transfer deadline day, with Sporting Lisbon having sanctioned a sale.
He has, however, been unable to join up with his new employers.
Fifa claim the deal is void because the final pieces of paperwork were completed after the deadline had passed.
Nice refute these claims and will now take their case to CAS in an effort to bring Djalo on board.
"We will refer the case to CAS in the next 48 hours," the club's chief executive Julien Fournier told L'Equipe.
"We hope the player will be allowed to play.
"Depending on the decision, which should be made early next week, Djalo will be able to play against Bordeaux on 15th October or from January onwards."