The Spanish giants head into their eagerly-anticipated Champions League clash with City at the Bernabeu Stadium on Tuesday night amid a poor run of form. Jose Mourinho's Primera Division champions have won just one of their opening four games this term but Silva fears a big European night might provide the spark to change that.
The Spaniard said: "It is clear that, when everything is going well, they play with more confidence. When they have doubts, it is difficult. But maybe it is more dangerous because they are not at a good moment and we could awaken the beast in them. We have to be careful - they are a world-class team."
Silva, 26, may already have delivered a blow to Real by signing a new five-year contract with City prior to flying back to his homeland. The World Cup and European Championship winner, signed from Valencia two years ago, had been linked with Los Blancos but has now committed to City until 2017.
Silva said: "I'm very pleased because I've been here for two years now and I feel very happy here at the club, in the city and with all the people. We've won the Premier League title and two other trophies too, and the team is growing and we are now aiming at the Champions League, and so that also is another reason to want to stay here and try and win it."
The match marks the start of City's second successive Champions League campaign and manager Roberto Mancini's immediate aim is to better last season's effort. City failed to get beyond the group stage a year ago despite accumulating 10 points from a difficult set of fixtures.
This time the task is tougher with respective Dutch and German champions Ajax and Borussia Dortmund also lying in wait.
Mancini said: "I think it was a good experience last year - we did a good group but it was not enough. I think it is important now that we go to the second stage. After February anything can happen, but now it is difficult to say what we can do."
Mancini has played down any suggestion of rivalry with his Real counterpart Mourinho. There is assumed to be tension between the pair over the way Mourinho succeeded Mancini at Inter Milan in 2008.
The Italian said: "We don't have a personal relationship. I met him two times for Porto against Lazio games and I met him in Milan, but I have only met him four or five times. I know him as a manager. I think it will be a good game, Real Madrid against Manchester City, but I think the most important thing will be the fantastic players on the pitch."
Source: PA
Source: PA