Arsenal manager Arsene Wenger said Diego Costa should have been sent off before Gabriel was red-carded in the Gunners’ 2-0 defeat against Chelsea at Stamford Bridge.
Costa was involved in several confrontations with Laurent Koscielny and lashed out at the defender.
Costa was booked, as was Gabriel, but Gabriel then kicked out as the sparring continued and was dismissed.
Wenger said: “It was surprising Costa got away with what he did. He can do what he wants and stays on the pitch.
“I think it is unacceptable behaviour what he does to Koscielny. He pushed him in the face and gets away with it. I don’t understand [referee] Mike Dean’s decision.
“I accept the Gabriel decision. He deserves it. Costa goes down from very little but Gabriel should not have done it.
“But Costa will do the same next week and the week after and get away with it.
“We expect that kind of game but you expect the referee to make the right decision.”