The Chilean manager doesn't believe the destiny of the Premier League title will be decided when his side take on the Reds at Anfield next weekend
City moved to within a point of the Reds having played a game less than their rivals with a 4-1 win over Southampton but were far from convincing in seeing off the Saints.
Nevertheless, the three points enabled Pellegrini's side to close in on the leaders and crank up the pressure ahead of their trip to West Ham United tomorrow afternoon.
The Chilean, who was left unimpressed by his side's slack first half showing, does not believe next Sunday's encounter, however, will have too major a bearing on who will win the league this season.
"I was very sure that Southampton was going to be a difficult game for us," Pellegrini told BT Sport. "Now we have an important game against Liverpool, they have to play tomorrow so we'll see what happens.
"There's a lot of time to prepare so it's an important game but I don't think that game will finish the Premier League. After that we play six games more and Liverpool has to play four."
City started with a bang thanks to Yaya Toure's early penalty but Southampton responded with a stirring fightback and levelled through Rickie Lambert, with a penalty of their own.
But a quickfire double on the cusp of half-time, including Samir Nasri's hotly-disputed strike, gave City some breathing space which they never looked like relinquishing.
Pellegrini bemoaned his side's indifferent start to the match but felt it was ultimately a game of two halves.
"I think it was a very different game from the first half to the second one," he told reporters. "The first half we did not play very well because we had players between our lines so we never recovered the ball well enough against a team who have a lot of possession and technical players.
"But in our worst moment we scored three goals and really I do not remember Southampton having too many chances to score when they had the ball.
"We finished the first half at 3-1 and maybe it was the difference between the two teams. But in the second half we had a better performance. We played very well, we scored one goal more, we had three or four clear chances to score, we had more possession and recovered the ball well."
Nasri's goal, teed up by an offside David Silva, was one of the main talking points after the game but Pellegrini did not believe the incident had a direct impact on the game in any case.
He added: "I haven't seen the goal but the referee decides. If the referee made a mistake maybe it's important but I don't think just one goal was the difference between Southampton and our team today."