According to Canal+, Lyon duo Memphis and Mendy had a physical fight during a training session on Thursday. On the same day, teammates Fekir and Marcelo also came to blows.
Memphis Depay and Nabil Fekir were reportedly involved in a physical altercation with Lyon team-mates on Thursday.
Both Lyon stars were dropped for a Ligue 1 clash with Nantes and reports in France claim their demotion to the bench was due to a training ground bust-up.
Canal Plus claim Fekir came to blows with centre-back Marcelo, while Depay also had a physical confrontation with left-back Ferland Mendy.
None of the four players involved were included in the starting line-up against Nantes – an injury to Mendy meant he was unavailable for selection.
The news of Depay and Fekir being involved in scuffles will peak the interest of several Premier League clubs linked with the attacking pair.
Liverpool have been tipped to make a transfer move for Depay, while Fekir has been linked with Manchester United and Chelsea since his switch to Anfield collapsed last summer.
Depay may have started the game on the bench, but was called into action just after the half hour mark.
Anthony Limbombe scored a late winner for Nantes in the 2-1 victory, condemning Lyon to their third successive loss in all competitions.
Lyon president Jean-Michel Aulas hit out at his players after the defeat, but denied any fights had taken place at the training ground.