As happened before to FC Barcelona, Real Madrid and Atlético de Madrid, Villarreal (along with Valencia, Chelsea and Manchester City) will be investigated by FIFA in the case of signing underage players.
Like before, the articles used for this are Article 19.1 and Article 19.2 of the Regulations on the Status and Transfer of players (page 17). No names about which players could be investigated, but this is not a good sign.
Article 19.1 doesn’t allow transfers of a player under the age of 18 while Article 19.2 allows some situations in which the transfer would be legal like the parents moving to the country for reasons not related to football or a maximum distance of 100km between player residence and club headquarters
In case the investigation proves Villarreal to have done something wrong, will receive a fine and two consecutive transfer window without the possibility of signing players