FC Barcelona president Josep Maria Bartomeu has slammed out-going Arthur Melo, who refused to return to training.
The Catalan giants are preparing for the second leg of their UEFA Champions League tie against Napoli next week.
Arthur, who will join Juventus next season, did not turn up for training this week and has angered the club bosses.
"What Arthur has done shows a lack of respect for his team-mates because the team wants to do well in the Champions League," Bartomeu told SPORT.
"It is not logical that playing for such an important title, a player decides to remove himself. It is unjustifiable and totally incomprehensible.
"We reached the agreement that until the Champions League ended he would continue playing for Barca, both in the league and in the Champions League. He is a player who has a certain importance in the team and who could help us.
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"But he did not appear from the return of the mini-vacations. It is an unacceptable act of indiscipline. And that is why we have opened a file for him, because there is no argument to justify his absence.
"He called and said, 'I will not return, I will stay in Brazil'. It is his decision. No one has given him permission."