Although it's a game that had to be played in December, the current registration rules
This Wednesday, FC Barcelona have to play against Sporting Gijón the match of the 16th round of La Liga. It had to be played in December, but it was impossible because Barcelona was participating in the Club World Cup. So if it had been played in the original date, Arda Turan and Aleix Vidal could have not been able to participate, as FIFA's ban which prevented new signings to play ended in January.
So, taking into account that, will they be able to play this match next Wednesday? The journalist Xavi Campos explained in Catalunya Radio that FC Barcelona asked it to La Liga, the Spanish Federation and Sporting, and they all agreeded that these Barça players can participate in the match. In the same way, they agreeded that the footballers Sporting signed during winter market will also be able to play. So Arda, Vidal (Barça), Lichnovsky and Vrjanjes (Sporting) won't have problems if they play.
With this move, FC Barcelona wanted to avoid a possible wrongful lineup which could have meant the loss of three points.