Arsenal striker Robin van Persie says they feel "betrayed" after he was sent off in defeat at Barcelona.
Van Persie received a second yellow card for kicking the ball after the whistle had been blown.
The Dutchman labelled his red card "a total joke".
"I think it's a total joke - how can I hear this whistle with 95,000 people jumping up (and shouting)?"
Just a second elapsed between the referee blowing his whistle and Van Persie striking the ball, and the latter continued: "That makes it even worse. I cannot understand that view from the ref.
"If there were four, five, six seconds in between, you can make a check (for offside). One second, it's a joke.
"I tried to explain there were 95,000 people jumping up, how can I hear the whistle?
"He's been bad all evening, whistling against us. I don't know why he's here tonight.
"We feel betrayed a bit, when it was 1-1 it was all to play for and in my opinion this referee killed the game."
