Barcelona are to make a final appeal to FIFA in an attempt to bring forward Arda Turan's registration before taking the matter to the Court of Arbitration for Sport (CAS).
Turan joined Barca from Atletico Madrid in July but is not eligible to play for the Spanish champions until next year because of a transfer ban imposed on the club.
The embargo, which came about as a result of Barca breaching rules relating to registering youth players, expires on January 4.
But, following a cruciate knee ligament injury suffered by Rafinha last month, Barca enquired with FIFA and the Spanish Football Federation over the possibility of fast-tracking the Turkey star's registration.
That request was rejected by FIFA, although the Spanish and European champions have since called for a "more concrete answer" and hinted they could take the matter to CAS.
And Barca have now confirmed they are to make another plea to FIFA's Appeals Committee on Thursday, which the club said will serve as a "prelude" to an appeal to CAS.
