City became the worst performing English club in the history of the competition.
Mancini said: "Our targets have not changed. Our main target was the Premier League and FA Cup - to win a trophy.
"We wanted to get to the Champions League second stage - then in February. when you're there, you can change your target. But we didn't and now we can't.
"I don't feel any pressure. I'm disappointed because we went out of the Champions League and I'm disappointed for the club because they deserve to go through and for our players, who deserve to play on that stage."