The Football Association has asked FIFA to ratify Adrien Silva's £22m transfer to Leicester City, the world football governing body has revealed.
Leicester thought that they had landed the midfielder from Sporting Lisbon on transfer deadline day, only for FIFA to block the transfer as it was 14 seconds past the extended deadline.
FIFA have since withheld the International Transfer Certificate for the Portugal international and the Foxes have been preparing an appeal.
A FIFA statement read: "The Football Association has requested a formal decision of the single judge of the Players Status Committee be authorised to request the International Transfer Certificate for the player Adrien Silva outside the registration period and register him with Leicester City.
"The matter is currently pending and therefore we are not in a position to comment further."
A decision from the Players Status Committee is usually issued within 30 days of a valid request, which means that the issue could be resolved by the end of October.
Silva is currently not allowed to train with the Foxes, although the 28-year-old has been working with the fitness coaches at their Belvoir Drive training ground.