Arsene Wenger has said that Diego Costa "should have been sent off" twice during Arsenal's 2-0 defeat to Chelsea.
Costa was involved in a scuffle with Gabriel Paulista after the forward had pushed Laurent Koscielny to the ground.
The incident led to Paulista getting sent off for retaliation while Costa only received a yellow card.
This left Wenger furious, claiming the Chelsea striker got away with his actions on the pitch.
"I cannot understand this situation. Costa, twice should have been sent off," Wenger is quoted as saying by Goal.com.
"Look at the situation before the cross comes in. He hits Koscielny in the face on purpose. He makes a fuss of it and in every game he is aggressive and gets away with it because of the weakness of the referee.
"I think two sendings-off for us and Costa staying on the pitch is a shame."
Arsenal remain fourth in the Premier League table for the time being.