Pellegrini was a forlorn figure on the sideline Wednesday as his side needed a late Samir Nasri goal to escape with a 2-2 draw against rock-bottom Sunderland.
City has a game in hand but is six points behind table-topper Liverpool, which beat it 3-2 at Anfield on Sunday.
Chelsea is just two points behind Liverpool and knows it can win the league by securing victories in its remaining four fixtures, with a trip to Anfield still to come for Jose Mourinho's men.
Ahead of City's home clash against West Brom on Monday, Pellegrini stressed that the title race was not over.
"I am absolutely sure the other teams will drop points in the same way we did in the last game," he told reporters. "We have 15 more points to play for and we will try and win the most amount of points.
"Then, at the end of the season, we will see who has the title. All of us want to win as much as we can. We must try to finish this season in the best way."
Pellegrini confirmed that the midfield trio Yaya Toure, David Silva and Jesus Navas would miss out again Monday but does not feel that City's title chances have been significantly harmed by their recent absence.
"There has been an important amount of injuries during this season but not only for our team," he added. "We have played so many games with a lot of intensity but normally all the other teams who play in all the competitions have a lot of injuries. Of course it is a problem."
He also shrugged off speculation linking City with a huge bid for Barcelona star Lionel Messi in the offseason.
"It is not a surprise for me to me to hear all different rumors about players that come and go," he said. "It is the same thing the whole year. Remember all the goalkeepers that we were [supposed to be] bringing here?"