The Frenchman has been out of action with a groin strain since the 1-0 defeat to Bayern Munich last month.
However, Pellegrini claims that the 27-year-old should return to full training by the end of next week, putting him in contention for the Manchester derby on the following Sunday.
"Samir Nasri is recovering from his surgery," the Chilean told reporters.
"I don't know exactly but I suppose that end of the next week he will start working with the whole team again."
The Premier League champions host Tottenham Hotspur at the Etihad Stadium tomorrow afternoon at 12.45pm.