Barcelona want to use Arda Turan, their star signing from the summer, although the FIFA sanction prevents them from registering new players until January 4.
The injury to Rafinha, which saw him rupture his cruciate ligament against Roma, has opened a door for the Turkish international.
Barcelona are trying to take advantage of the chance to register a new player in the case of a long injury, as Rafinha has, which may keep him out until the end of the season, to register Arda.
They have asked the RFEF if they can add Turan, and also FIFA too, but according to Cadena COPE that will be very difficult because the world football governing body do not like the Spanish rule of replacing players with long-term injuries.
Arda's agent, Ahmed Bulut, says that the midfielder feels physically and mentally ready to play for Barcelona. "It will not be easy to convince FIFA," he told RAC-1. "Arda didn't think he would play until January, but he is ready. Arda feels at home at Barcelona. The injury to Rafinha is bad news - for him it would be good to play already."