The North-West outfit will host the current league leaders at the Etihad Stadium on Sunday following a run of three winless games.
"We like to think of ourselves as big-game players, so we need to step up again on Sunday," The Telegraph quotes Hart as saying.
"It's a big week for us. We've not won for a little while, so we need to step up. We need to win, it's a close Premier League, they are a title rival, and we need to beat them."
City are currently fifth in the league table, five points adrift of Chelsea.