Pablo Zabaleta has accused French referee Stephane Lannoy of making "shocking decisions" in Manchester City's 2-1 Champions League defeat to Barcelona, including refusing to give Manuel Pellegrini's team a penalty.
Zabaleta, 29, had already been booked and was shown a second yellow card in the Nou Camp for his complaints when Lannoy refused to award a spot kick after Edin Dzeko went down under Gerard Pique’s challenge.
And the former Espanyol right-back was bemused as to why he was given a red card for his protestations.
"It was very clear," he told national newspapers. "I think Pique was behind me and made the tackle on Edin Dzeko and the referee was only two metres away from that.
"I don't know why I was sent off. I went to him to talk to him in a good way.
"I was a little bit angry to him because he didn't give a penalty but I have always been very respectful to him. I am frustrated. I think it was a shocking decision.
"Sometimes in the game you are nervous because you are trying to get the result, and sometimes shocking decisions by the ref make you a bit angry."
Lannoy and his assistants were also criticised for denying Barcelona a penalty when Joleon Lescott seemed to foul Lionel Messi, and for ruling out a Neymar goal when replays proved Jordi Alba was not offside.
And Zabaleta argued City should have received a free kick before Barca opened the scoring, saying: “It was also a foul against Dzeko just before Barcelona’s first goal.
"He held the ball and turned, and Pique had hold of his shirt, and the ref gave a free kick to Barcelona."
City went out 4-1 on aggregate after a 2-0 first-leg defeat at the Etihad Stadium, when Pellegrini was also unhappy with the officiating.
The Chilean's comments about referee Jonas Eriksson, who awarded Barcelona a penalty and sent Martin Demichelis off, brought him a two-match touchline ban.
Pellegrini has maintained that the referee decided the first game and captain Vincent Kompany -- who scored his side’s goal in the Nou Camp -- pointed to the fact that Barcelona only scored once, through Messi on Wednesday, before City were reduced to 10 men.
"Over the course of two games, whenever there was 11 players [against 11], there wasn't much between the two teams," he said.
"Messi is an incredible player and whenever he has the ball danger can happen, but outside of that we had huge chances. If we score, we're looking at a completely different game."
Los Blaugranas boss Gerardo Martino was diplomatic about the officiating, saying: "That happens. In first game it was said ref favoured us but Pique had a good goal ruled out. We had another Neymar goal ruled out here, but refs make mistakes."
Sergio Aguero, meanwhile, told El Larguero: "I do not know about that, [Zabaleta] was pretty angry in the dressing-room about what happened. I asked him what happened and he said it was about the penalty.
"The truth is I never get involved with the referees. If they do not whistle they do not whistle. They can make mistakes too."