Barcelona president Josep Maria Bartomeu has hit out at the Court of Arbitration for Sport's decision to uphold the Catalan outfit's two-window transfer ban.
Barca were hit with the ban in April after FIFA found that the Spanish club breached rules in relation to signing youth players.
Barca appealed the decision, but the CAS upheld the two-window transfer ban on Tuesday.
"A great injustice has been committed today - an injustice for Barca, for all the children and parents affected by this decision, for all the club members and for football in general," Bartomeu told the club's official website.
"We have always made it clear that we consider FIFA's sanction to be disproportionate. This judgement by CAS, which ratifies FIFA's decision, is not good for us and defies all sporting logic."
As it stands, Barcelona cannot sign any new players until January 2016.