Lyon have demoted Brazilian centre-back Marcelo to the reserves due to "inappropriate behaviour", the club announced on Tuesday.
French media reported the two sides were negotiating ending the 34-year-old's contract.
In a statement, the Ligue 1 outfit said Marcelo's behaviour in the dressing room was "inappropriate" following Sunday's 3-0 loss to Angers, in which he scored an own goal.
The club said the decision was "taken unanimously by Lyon's management team."
They said they had told the player on Monday afternoon.
Marcelo arrived in 2017 from Istanbul club Besiktas for 7 million euros ($8.2 million)
He has played 170 games for Lyon and was captain in the 2018-19 season.
The following season he became a target of the club's ultras in a campaign that reached a climax during a Champions League victory over Benfica, a game in which he came off the bench. He reacted angrily as supporters held a banner telling him to "clear off". He said he was the target of abuse and missiles.
He made peace with fans last winter.
He was a regular starter last season as Lyon finished only seventh and signed a two-year contract extension in March.