Atletico had been hoping that a successful appeal would see the two-transfer window ban reduced to just one, which had already been served in January 2017. City rivals Real Madrid were issued with a similar ban at the same time and had already seen theirs reduced.
Real can bring new faces in this summer as a result, but Atletico haven't been so fortunate.
Atletico have had the financial penalty reduced, but are understandably dismayed at the overall decision. A club statement described the verdict as 'discriminatory'. The club also maintains is has always complied with regulations and suggests that the delayed release of the verdict is tantamount to a lack of respect.
The ban will not strictly prohibit Diego Simeone's side from signing new players, but they will not be able to officially register them for competition until next year. Barcelona famously signed Aleix Vidal and Arda Turan in 2015 while serving a ban, but both players had to wait six months before they were officially allowed to play.
It remains to be seen what impact Atletico's failed appeal will have on their summer plans. The club struck an agreement to sign Alexandre Lacazette from Lyon last month. That move could well now be scuppered unless the striker is prepared to sit on the sidelines until January.
Any chance of Diego Costa returning to Madrid from Chelsea is more than likely dead.
The club insists it has planned for two eventualities, one if the ban was to be reduced and one if it wasn't. The statement further read, "The club will move forward in the negotiations necessary to formalise the operations to register players from the 1st of January."
Atletico may also be more unwilling to allow players to leave the club given that they cannot replace anyone, unless they promote from within, and would therefore be weakening their squad.
The most high profile of the potential departures is Antoine Griezmann, a serious target for Manchester United all season. The problem there lies in the fact that it was expected that United would trigger the Frenchman's €100m release clause, cutting Atletico out of the negotiations.
The club's only real hope on that front is that they can convince Griezmann to reject all offers from Old Trafford this summer and not leave them in the lurch in light of Thursday's CAS verdict.
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