Barcelona have been handed a €602 (£503) fine following a complaint from Atletico Madrid over their pursuit of striker Julian Alvarez during the summer transfer window, according to Mundo Deportivo.
Atletico accused their La Liga rivals of approaching the Argentina international without first notifying the club in writing, allegedly violating regulations governing contact with players under contract.
The Spanish Football Federation imposed the fine, while FIFA reportedly chose not to get involved.
Alvarez joined Atletico from Manchester City in August 2024 in a deal worth up to £81.5 million, signing a contract that runs until June 2030.
The 26-year-old has since faced criticism from sections of the Atletico fanbase after publicly expressing his desire to fulfil his dream of playing for Barcelona this summer.
However, he attempted to ease tensions on Saturday after scoring the winning goal against Deportivo La Coruna, apologising and admitting that his previous comments were a mistake.
His apology may do little to change the situation, particularly as Alvarez is reportedly preparing to appoint Rodri's agent, Pablo Barquero, to manage his professional affairs.
Barquero played a key role in facilitating Rodri's move from Manchester City to Barcelona this summer, and there could be expectations for him to pursue a similar deal involving Alvarez next summer.
For a club with Barcelona's financial resources, a €602 fine is practically insignificant.
The punishment is unlikely to make even the slightest difference to the club's finances, let alone discourage similar behaviour in the future. From Atletico's perspective, there is every reason to feel frustrated by the outcome.
Public comments from Barcelona officials have unsettled a player who remains an important part of Atletico's long-term plans.
Top clubs should not be able to openly pursue another team's contracted star and walk away with little more than a token penalty.
If football's governing bodies genuinely expect clubs to respect contractual obligations, they must introduce sanctions that carry meaningful consequences.
A fine worth just a few hundred euros does nothing to prevent wealthy clubs from testing the limits of transfer regulations.
Barcelona are unlikely to lose any sleep over the decision, while Atletico are left to deal with the consequences of a situation that could have a significant impact on their future plans.