The Spaniard, who missed last weekend's 0-0 draw at Stoke City and Tuesday's 3-0 win at Viktoria Plzen in the Champions League, has returned to training and could inject some verve into the side when they host the Premier League champions.
"The players who were injured were (defender) Micah Richards, he has worked normally with the whole squad, same thing (with) David Silva and (defender Gael) Clichy starts today," Pellegrini told a news conference.
"It's the first day for him (Clichy) so maybe he will not be ready for next Sunday but all the other players expect (Martin) Demichelis are fit, no problems."
City enjoyed a memorable start to the season with a thrilling, attacking display in a 4-0 demolition of Newcastle United but have since fallen somewhat flat in the league.
A shock 3-2 defeat at Cardiff preceded an unconvincing 2-0 win over another promoted side, Hull City, while Saturday's draw at Stoke offered little to inspire confidence in their title chances.
However, the midweek victory in European competition - and in particular the fantastic curling shot by Yaya Toure for their second goal - has raised spirits ahead of the meeting with their city neighbours and a manager against whom they have a poor record.
"Of course that always gives confidence to the players," said Pellegrini, who was also pleased to see captain and centre back Vincent Kompany come through 90 minutes in Plzen on his return from injury.
United manager David Moyes, who like Pellegrini will be tasting his first Manchester derby, boasts an excellent run of results against City from his time as Everton manager, winning six of his last eight league meetings.
It is a record Pellegrini is aware of but he has his own statistic to throw back.
"I always have a good record against him when he was managing Everton when I was managing Villarreal," said the Chilean, referring to the 2005 Champions League qualifier between the Spanish side he then managed and Moyes' Everton.
Villarreal won that third qualifying round tie 4-2 on aggregate, beating the Merseyside team 2-1 in both legs, and went on to reach the semi-finals of Europe's elite club competition.
"It was a very special game. Both teams were playing for the first time in the Champions League," he said. "It was a very difficult game, first at Goodison and we finished beating Everton at home."