The Premier League champions need to win both their remaining Champions League games to stand a chance of progressing to the last 16.
"Our concentration must be very high," said Mancini. "We will be playing against top players and it will be an important game.
"They have a big history. They've won a lot of Champions Leagues. We need to work a lot to be at their level.
"But I do think we have the players who can beat them. It is possible."
City are currently at the bottom of Group D with just two points from four matches.