Sergio Aguero is poised to give Manchester City a huge boost and return to action in his side's FA Cup third-round replay against Blackburn on Wednesday night.
Aguero, who has scored 19 goals this season, has missed eight games after suffering a calf injury in the 6-3 thrashing of Arsenal on December 14.
Pellegrini has not yet decided if Aguero will feature as Blackburn visit the Etihad Stadium, but the Argentinian is in contention for a bench spot.
The Chilean said: "Sergio is working with normality with the whole squad and he is on Wednesday's squad list.
"He is a very important player for us. It doesn't matter if we are scoring a lot of goals, Sergio will always be a very important player and we are happy he is coming back."
City drew 1-1 with the Championship side in the original tie at Ewood Park but Aguero's return is timely with Samir Nasri ruled out for around eight weeks with knee ligament damage.
Pellegrini said: "It is very important. We have not only important games, but a lot of games. All of them are important for us."
Nasri was carried off on a stretcher after being caught by a bad tackle from Newcastle's Mapou Yanga-Mbiwa at the weekend.
Pellegrini said: "He is a very important player for us. He was also playing in a very good moment so we hope he can come back as soon as possible but I think less than six or seven weeks will be difficult."
The Manchester City manager is wary of Blackburn ruining his club's home record and added: "They didn't surprise me, I think they played a very good match at home.
"I am absolutely sure that we must play a very good match if we want to win because they are very motivated.
"They are a very strong team, they know exactly the way they want to play.
"They are strong in defending, for counter-attacks, for different set-pieces and trying to score a goal. It will be very close."
Key midfielder Yaya Toure will miss the game having had an issue with a back injury while David Silva is also likely to be rested due to a niggle.