Manchester City will head in to next Sunday's derby game with United at the top of the Barclays Premier League but manager Roberto Mancini doesn't believe it is the most important game of his club's week.
City fans are understandably anticipating next weekend's game with some relish after seeing United stumble at Liverpool and their own under strength team put four past previously unbeaten Aston Villa at the Etihad Stadium.
But after a home draw with Napoli and a crushing 2-0 defeat at Bayern Munich in the round of Champions League games, City now prepare to host Villarreal on Tuesday night knowing that another defeat would be catastrophic.
'If we don't win then things will be difficult for us to qualify for the next stage,' said Mancini on Sunday.
'Certainly it would be impossible to finish top of the group. So, yes, we need to win.
'Everybody will talk about the derby game with United and I understand that. It is exciting.
'But I need people to focus on this Champions League game first. It is very important to us.'
Mancini has had a chequered history in the Champions League, with many observers in Italy saying the reason he lost his job at Inter Milan was due to his failure to come close to winning European football's biggest prize.
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'Yes, I have experience of the competition and I know what can happen.'
City beat Villa 4-1 with a starting eleven that didn't include Edin Dzeko, Sergio Aguero, Samir Nasri or David Silva on Saturday, a sure sign of how Mancini has managed to bring genuine strength in depth to his squad. All are expected to start against the Spanish side tomorrow at the Etihad Stadium.
City captain Vincent Kompany: 'Our experience in the Champions League so far has merely told me what we knew already, that this is a really hard group.
'I thought that when it was drawn and that is the way it is proving to be.'
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