Atletico Madrid have had their appeal against their transfer ban rejected by the Court of Arbitration for Sport.
The Spanish side were banned from making signings for two transfer windows, along with city rivals Real Madrid by FIFA in 2016.
Both clubs were said to have breached the rules over the transfer of foreign players under the age of 18.
The judgement means Atletico are unable to make any signings until January 2018, although they can sell players.
The development could also possibly affect a potential move away for Manchester United target Antoine Griezmann.
