Barcelona have reportedly sought legal advice over the circumstances of Antoine Griezmann's loan deal at Atletico Madrid.
The World Cup winner returned to Wanda Metropolitano on loan in 2021 after struggling to rediscover his old form at Barcelona, and he registered eight goals and seven assists in 36 outings last term.
Amid competition from Luis Suarez, Joao Felix, Angel Correa and Matheus Cunha, Griezmann started 24 La Liga games in 2021-22 but has struggled to make the first XI in the current campaign.
Diego Simeone has opted to start Griezmann on the bench in each of Atletico's opening four La Liga games, and he has featured for less than 30 minutes as a substitute on each occasion.
The 31-year-old did net against Getafe and Valencia off the bench - scoring the winning goal against the latter - but Simeone has hinted that he is under orders not to give the attacker too many minutes.
"You've known me for 10 years. I'm a club man and I always will be," Simeone explained to reporters when questioned on Griezmann's lack of starts.
Atletico are understood to possess an obligation to re-sign Griezmann permanently if he plays at least 45 minutes in 50% of matches this season, and the fee would be €40m (£34.6m).
Simeone's admission has led to the belief that Atletico chiefs have told the Argentine not to start Griezmann in order to avoid coughing up the payment to welcome the France international back to the Wanda Metropolitano permanently.
Now, Mundo Deportivo - via 90Min - claims that Barcelona are now considering taking legal action against the capital club, but it is unknown what specific steps the Blaugrana will take.
Griezmann remains under contract at Barcelona until the summer of 2024 and has amassed 35 goals and 17 assists in 102 outings for the Catalans, but he does not appear to be in Xavi's plans moving forward.
Barcelona already have a host of talented names competing for spots in the final third, with Robert Lewandowski cementing himself as the club's first-choice centre-forward since his summer signing from Bayern Munich.
Lewandowski's arrival opened the door for Pierre-Emerick Aubameyang to leave the club for Chelsea, while Martin Braithwaite has signed for Espanyol following the termination of his deal.
Memphis Depay was also expected to leave in the summer transfer window but has stayed to fight for his place in the Blaugrana XI, while Ferran Torres, Ansu Fati, Ousmane Dembele and Raphinha are battling for spots out wide.
Raphinha and Lewandowski were both on target for Barcelona in Saturday's 3-0 win over Sevilla, while Griezmann played 27 minutes in a 1-1 draw with former club Real Sociedad.
Barcelona and Atletico will both be in Champions League action this week, as Xavi's side take on Viktoria Plzen at Camp Nou in Group C while the Colchoneros play host to Porto in Group B.
