City face Liverpool at Anfield on Sunday with many tipping the winner of the clash to lift the Premier League trophy in May, but Pellegrini has attempted to play down the significance of the result on Merseyside.
The 60-year-old told reporters: "It's a very big game, but I do not think it will choose the title. Every game is a big game now until the end of the season.
"Liverpool have had a great season, so this is an important game. It's a very big game, it's the team who are at the top of the table.
"Of course the team that wins this game has more of a chance to win the title. But if you think that this is the finish of the Premier League, I think it is a mistake."
City currently sit four points behind leaders Liverpool, but the Chilean's team have two games in hand on their title rivals.