Adrien Silva has had his appeal to join Leicester City on a provisional basis turned down by the Court of Arbitration for Sport.
The midfielder's move from Sporting Lisbon to the Foxes was blocked after the paperwork for the deal was received by FIFA 14 seconds after the transfer the deadline.
Silva applied for "urgent provisional measures" which would have allowed him to play until the final appeal was heard, but CAS have rejected his motion.
However, they did say that the situation will go ahead "and a final decision on the merits will be issued after a hearing, which is yet to be fixed."