The Italian is expecting Pep Guardiola's side to be fired up as they try make amends for their surprise 4-2 defeat to Leicester at the weekend.
"I saw the game against Leicester. I was surprised, but in Italy we have a saying: 'Each game has its own story'," said Mazzarri.
"This won't help us. We will find Manchester City very angry and focused, we won't have the luck that they will underestimate us".
The Watford boss also believes that his side can "battle" for a victory against City, after the Hornets beat Everton 3-2 at the weekend.
"I said this to my players. If we put ourselves in front of our opponents we can fight against any Premier League team," the Italian said.
"If we are 100 per cent ready, we can play against any team in the Premier League and battle for the three points.
"This is something that gives us a lot of positivity before the game".