After completing a big-money move from Wolfsburg late in the transfer window, De Bruyne's debut was put off by the international break but could come on Saturday as they travel to Crystal Palace.
Pellegrini confirmed that the Belgian midfielder will be in the matchday squad, though did not say that he will definitely start, but is hugely optimistic about how his new signing will develop at the Etihad Stadium.
"Kevin is an important player - like Raheem Sterling, he has characteristics we need," the City boss told reporters.
"His position is easy to settle in our team. He will be a very important player for us. He's in the squad list; we'll see on Saturday whether he starts.
"He's a young player and he's improved a lot since he was last in the Premier League. I always say that, when good players arrive into a good team with good players, I think that they will continue to improve and that's why he's here.
"It's not the best way to arrive to go into international duty but these things happen; he must play for the Belgium team.
"In his position, it's easier to settle in – it's more difficult when you're a defender. It's different work.
"I spoke with him during the week, we worked for a couple of days and he's seen what the team is doing.
"I think that he can play in all three positions, on the wings or as a striker, with no problems."