Manuel Pellegrini's side trail leaders Chelsea by six points after nine games this season, and the Argentine is adamant that City have to beat Manchester United as they must not allow the gap to the Blues to widen.
"I think, on Sunday, it is about more than just three points and winning that game," Zabaleta told The Mirror.
"If we win it means we can get the confidence back - and that's something we need at the moment. We cannot drop points because of the race with Chelsea.
"We must be more consistent as a team. Individual performances have not been great this season and when you don't play well as a team, it's difficult collectively. We must put that right on Sunday."
City face off against the Red Devils at the Etihad Stadium on Sunday.