City moved up to second in the Premier League on Saturday, a point behind Liverpool, with a 4-2 triumph at Fulham representing their eighth win in nine games across all competitions.
However, the visit of Liverpool will see Pellegrini's men come up against the top-flight's in-form player.
Looking ahead to Thursday's match, Pellegrini noted the threat of Suarez and also suggested up to six teams remain in contention for the league title.
"(It will be) very difficult because Liverpool are a very good team," said the Chilean.
"Suarez is in a very good moment.
"We are just finishing the first half of the Premier League, two more games, (but) this Premier League is not only about Liverpool and Manchester City. Five or six teams will fight to the end."
