The Chilean insisted the Reds’ return in the early hours of Friday morning from their defeat in Istanbul against Besiktas would hamper Brendan Rodgers’ side – but would not prove pivotal.
With Chelsea involved in the Capital One Cup final later the same day, City can cut the London side’s lead at the top of the table to two points with a victory in the noon kick-off.
Pellegrini said of Liverpool’s late trip back from Turkey: “I think that of course it is an advantage, (but) not a decisive one because I always think the decisive thing is the performance on the day of the game.
“If we think we are going to win that game because Liverpool arrived last night, that is not the reason.
“But I have played in the Europa League and when you arrive on Friday it is not the best way to prepare for a game on Sunday – but that is the rules. They are playing Europa League.
“Maybe another time we (will) prepare worse for the game.
“We must play very well because they also have a strong squad. I don’t think they will play the same starting 11 as yesterday night. They are a strong team and it is a difficult stadium.”
Chelsea remain strong title favourites but City did claw two points back last week after hammering Newcastle at the Etihad and Pellegrini wants to take advantage of the Blues’ cup distraction this Sunday.
They must also put to one side their 2-1 Champions League home defeat to Barcelona for the trip across to Merseyside.
He said: “Of course it is important, and more than psychologically it is important mathematically.
“If we are going to have three points more, we are going to go two points behind Chelsea. It is very important to beat Liverpool and to continue winning in the Premier League, and continue fighting until the end to retain the title. As soon as we close the gap it is better for us.”