City have learned that they will face a UEFA hearing on November 17 over the missiles mainly rolled up balls of paper that were thrown on to thefield during the club's 2-1 Champions League win over the Spanish club.
But it will be Aguero who faces the toughest examination next month after he upset his opponents following his last-gasp winner at the Etihad Stadium.
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Villarreal vice-president Jose ManuelLlaneza and defender Carlos Marchena criticised the former Atletico Madrid striker after players from both teams exchanged insults in the tunnel at the end of the game.
It is understood that Aguero was heard singing a song in Spanish as he left the pitch and that this couldbe what has upset Villarreal.
Vice-president Llaneza said: 'What he did doesn't say much for him. It seems to me a lack of respect, ethics and comradeship.
On the mark: Aguero slots home to secure the 2-1 victory
'I thought he had learned something more. What I'm saying concerns Aguero's attitude. I don't understand whyhe makes fun of fellow professionals for losing.
'He is a player who has a lot to thank Spain for. He is an important player who should behave like one in moments like this.'
Marchena, who scored an own goal in the first half on Tuesday, added: 'Infootball you have to have class, especially in moments like this.
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'What Aguero did is not worthy and especially how he did it. These situations are a shame and they tell youabout the person who does them.
'You have to be a good person as well as a good sportsman, and showclass which he hasn't got.'
On his player's anger on the pitch, Villarreal manager Juan Carlos Garrido said: 'The players were emotional. They thought the goal was offside. It wasn't.
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'I think we have done a good match and we did deserve - if not to win - a 1-1 (draw). 'I thought we had a good match in general, in all aspects, and to lose in the last minute inthis way is difficult.
'Congratulations to City because they won but we thought we deserved more from this match.'
City did not officially respond to the Villarreal comments but Aguero did refer to it on his Twitter page. He said: 'I have no interest in getting involved in controversies, but Ihave to deny having mocked a Villarreal player.'
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