Marseille manager Igor Tudor vented his frustration at Nuno Tavares for 'losing his mind' after the left-back was sent off for kicking out at an opponent in Monday's 2-1 win against Montpellier.
The on-loan Arsenal star netted Marseille's opener in the 47th minute but went from hero to zero late in the second half, needlessly lashing out at full-back Arnaud Souquet to reduce the hosts to 10 men three minutes from time.
The depleted outfit subsequently conceded a penalty in injury time but held on for all three points despite the nervy finish.
Tavares' horror tackle sparked a mass brawl between the two Ligue 1 sides as Montpellier players quickly crowded around the 22-year-old.
After a quick VAR review at the pitchside monitor, referee Ruddy Buquet rescinded his original booking and brandished a straight red card, sending Tavares down the tunnel for an early shower.
In his post-match interview, Marseille boss Tudor confessed: 'He lost his mind and will get a good fine.
'These are things that happen, of course. He will learn a lesson for the future.'
The Portuguese star could miss Marseille's next three league matches against Troyes, Lorient and Monaco if his challenged is deemed violent.
Tavares has been otherwise enjoying his loan spell away from the Emirates this season, scoring five goals in 22 matches for the Ligue 1 outfit.