New Paris Saint-Germain manager Unai Emery has hinted that he could prevent Marquinhos from playing for Brazil at the Rio Olympics.
Marquinhos, 22, was named in the Brazil squad to take part in next month's games and the defender indicated last month that his club would allow him to take part.
The Olympics is the only major tournament that Brazil have never won and, as a player that fits the under-23 age criteria, Marquinhos would be a key asset for the host country.
His involvement would see him miss the start of the new French league season, however, and Emery, 44, has suggested that the former Roma defender might be better off skipping the competition.
"I've spoken a lot with the president and [sporting director] Olivier [Letang] -- we know the importance of the Olympic Games for Brazil and for Marquinhos," Emery told French radio station RMC.
"But we also know that PSG is important, like participating from the start and being there for the whole month of August. For the club, it's better that the players might be with us."
PSG are under no obligation to release Marquinhos for the Olympics and he was already part of Brazil's squad for last month's Copa America in the United States. He played two matches as they failed to make it past the group stage, a result that saw manager Dunga relieved of his duties.
Marcos Barros, father of Marquinhos, said that his son, who got married earlier this week, was on his honeymoon in the Maldives, but added that his agent, Giuliano Bertolucci, is en route to Paris to discuss the matter with the club.
"It's a surprise to hear this. Marquinhos is a PSG player and he has much respect for his club. But this was his decision to participate [in the Olympics]. We are going to go there [Paris], we are going to talk about this and we are going to try to arrange it so that he can play in the Olympics," Barros told Globoesporte. "Marquinhos has played for PSG for three years. He is not afraid of anything, nor that PSG would hold this against him. He has not confronted anyone. This was his decision.
"People have to understand the human side of things. We are going to do talk about this calmly, which is the best way for Marquinhos.
"PSG never said no. Since the speculation began about Copa America and Olympics, Marquinhos indicated that he was available for both competitions.
"The Copa America didn't interfere with their decision to release him or not [for Olympics] because PSG were practically obligated to release him for Copa America since it was a FIFA event. For the Olympics, Marquinhos' position is that he is wants to go and he is available."