Arsene Wenger is likely to face another UEFA ban after he confronted Slovenian referee Damir Skomina in the tunnel following Arsenal's 3-0 win over AC Milan on Tuesday night.
Despite the heavy victory, the Gunners fell agonisingly short in their bid overcome a four-goal first-leg deficit and were eliminated from the Champions League.
The 62-year-old Arsenal boss, who allegedly swore at Mr Skomina after the game, said: "I was not happy with the referee because he gave them many free kicks in the centre of the park.
"Every single free kick, every time they went down it was for them. They sensed that very quickly on the pitch, the players, and they used it very well."
Wenger was also far from happy with the playing surface in the San Siro during the first leg last month, which Milan won 4-0.
He added: "It may be an easy excuse but I feel UEFA has a lot to answer for because when you arrive at 7.46pm you get fined, but you can play on a bad pitch and they don't say a word.
"It's unacceptable from UEFA that they accept pitches like we had in Milan."
If Wenger is banned from the touchline it will be his second such punishment in 12 months, after he was reprimanded for comments he made about the officiating referee during Arsenal's Champions League exit to Barcelona last season.
