According to Spanish newspaper ABC, Vidal has filed a complaint against his club to La Liga and the Spanish Footballers' Association.

It is alleged that the Chile international has only been paid €1.7 million ($2.7 million) of the €4.1 million ($6.6 million) he is owed.

Vidal, strongly linked with a January return to Serie A, is frustrated at being underpaid but is leaving the legal matter to his representatives.

"I'm not in charge of that - that's why I have my agent, my lawyer, who takes care of the awards and stuff," Vidal said on Chilean radio. 

"It seems unfair to me if money is missing, but it is an issue that is alien to what we are experiencing today."

Vidal has started only four LaLiga games for Barcelona this term and earlier this week refused to rule out a move to Inter Milan in the upcoming transfer window.

However, the ex-Juventus and Bayern Munich star — a reported €18 million ($28.9 million) signing in August 2018 — is not thinking about his future while back in his native Chile for a short Christmas break.

"It's a subject I said when I arrived here that I'll talk about it when I'm there [in Spain]," he said.

"I'm on holiday and I just want to talk about what's going on here."