Marseille head coach Rudi Garcia disapproved of Patrice Evra's actions after the veteran full-back was sent off prior to kick-off on Thursday for appearing to kick a supporter.
Former Manchester United and Juventus defender Evra became the first player to be sent off before kick-off in a Europa League match following a pre-match altercation prior to Marseille's clash at Vitoria Guimaraes, who triumphed 1-0.
Evra, who has been criticised for his poor form this season, was warming up for the Group I fixture when the 36-year-old and his team-mates were confronted by fans - believed to be supporters of Marseille - at the front of the stand at Estadio Dom Afonso Henriques.
It sparked wild scenes as Evra fought back, lashing out at one supporter with an apparent kick to the head, and Garcia had some advice for the 81-time France international.
"Pat has experience, and he must not react. It's obvious," Garcia told beIN Sports.
"Patrice is a more than experienced player and we cannot respond, of course, to insults as low as they are and as incredible as they are because they come from one of our supporters."
Garcia added: "He is not a supporter of OM, because you cannot insult your own players, you have to be behind everyone."
Marseille succumbed to an 80th-minute strike from Paolo Hurtado away from home against Vitoria.
The result left Marseille second in the Europa League group, two points adrift of Salzburg and two ahead of Konyaspor with two matchdays remaining.