Adrien Silva is now training with Leicester while the Premier League club consider going to the Court of Arbitration for Sport over his transfer saga.
The Foxes' appeal to FIFA to secure the registration of Portuguese midfielder Silva was last week rejected by world football's governing body.
Leicester and the Football Association had asked FIFA to ratify the transfer after the paperwork for Silva's £22million deadline day move from Sporting Lisbon was submitted 14 seconds late.
That request was denied and, as things stand, the 28-year-old will now not be registered to play for Craig Shakespeare's team until January.