Mancini also has left the door open for Carlos Tevez to come back and team up with Aguero for a title push next season.
"Sergio is a top player and he's only a young guy. He's scored a lot of goals and I expect him to score a lot for us.
"He needs to get to know the Premier League because it's so different to La Liga.
"But I think after two months he will understand the game here and will score goals and win trophies with us."