A general favouritism towards the big teams means that, in Iñaki Williams' opinion, Barcelona are one of the last clubs around who can claim some kind of deficit in refereeing decisions.
Centre-back Gerard Piqué has led the Blaugrana frustrations after feeling that they'd missed out on clear penalties against Williams' Athletic Club and Villarreal.
"There are the last team who can complain because they are a big team and at the end of the day, there is always some favouritism," the Spanish striker told Marca.
"If I miss a one-on-one, then how are the referees not also going to get things wrong? They are human, just like the players."
"The referees have it very difficult and I don't like to protest so that the referees are not filled with doubt."