Arsene Wenger has said that Diego Costa should be investigated by the Football Association after the altercation with Arsenal defender Gabriel Paulista.
Paulista was sent off for his involvement in the incident but Costa received no punishment as Chelsea ran out 2-0 winners.
"He will do the same again next week and the week after that and he always gets away with it," Wenger told reporters. "[Taking retrospective action] is the least they can do.
"Costa can do what he wants and yet he stays on and everyone who responds to him has to be sent off. He hits Koscielny in the face yet he gets away with it.
"I understand referee Mike Dean's decision to send Gabriel off. He was guilty and should not have got involved but why does Costa stay on the pitch after what he has done?"
Arsenal will meet North London rivals Tottenham Hotspur in the League Cup on Wednesday evening.
