Manchester City manager Roberto Mancini believes "anything is possible" for his side in the Champions League after their 3-0 win at Villarreal.Two goals from Yaya Toure and a Mario Balotelli penalty gave City three points and a win in Napoli would seal their progress from the group stage.Mancini said: "If we make the knockout stages then anything can happen because we're a good team."We are going very well and want to improve if possible."City's debut Champions League campaign started slowly, with a draw at home to Napoli followed by a 2-0 defeat at Bayern Munich, which was soured by a row with striker Carlos Tevez.But Mancini's side have won seven games in a row in all competitions since then and were never troubled as they swept past Villarreal."I enjoyed this performance," added Mancini.Cannot play media. You do not have the correct version of the flash player. Download the correct version"Villarreal were missing four or five key players but it's still difficult to win away."We had 65% possession and scored three good goals, which is good for confidence."The team have improved in this competition since the first group match."Although City are three points from qualifying, Mancini is aware that his side will face a tough task against Napoli on 22 November."It's always difficult to play in Naples, although we want to win," added the Italian."There will be 70,000 in the stadium, so it will be tough conditions."Meanwhile, Mancini said that David Silva's injury was not serious after the midfielder was forced to come off with a back problem in the 65th minute of Tuesday's match."I don't think it's serious, he took a knock in the back," said the City boss."In 60 hours we play QPR. I think he'll recover in that time."