The Chilean saw his side drawn against the four-time winners Monday, but does not think the current side holds a candle to the one that last won the trophy in 2011.
"I think Barcelona will be very concerned that they have drawn us," he told reporters. "They are not the team of two years ago. The Bayern Munich result has given us a lot of confidence. We are improving every day and we must continue to improve. I think it’s a beautiful game, two very good teams."
City director of football Txiki Begiristain, who used to play for and represent Barcelona, is also confident, adding to Sky Sports: "I think it will be a great match. Ours is a team with a lot of confidence especially after winning against the champions [Bayern] in Munich. That will give us a lot of confidence — not just at home but away as well.
"We have to be confident because of the way we are playing. We are showing that we can score in all matches. This is important in the Champions League. We scored in Plzen, in Moscow, in Munich — it should give us confidence to play against a team who have been champions many times. Our manager knows perfectly Barcelona because he managed in Spain for a long time. In this sense, we are confident."
Elsewhere, Chelsea was drawn against Galatasaray, meaning a return to Stamford Bridge is in the cards for Didier Drogba.
The Ivorian scored the decisive penalty when the Blues won the Champions League against Bayern Munich in 2012, and club secretary David Barnard is delighted to welcome him back to west London.
"It was sort of written that Didier would come back to the Bridge," he told Sky Sports. "Obviously from Chelsea’s point of view, and the Chelsea supporters’ point of view, Didier will become a Chelsea legend because he gave everybody at the club their finest moment by stroking that penalty home in Munich, so he will get a fantastic reception. We just hope that when he soaks up that adulation he will be too tired to play the game. We’re looking forward to having Didier back."
Arsenal got a sense of deja vu when it was drawn out of the hat against Bayern Munich for the second time in two seasons, and the club's secretary, David Miles, says it is "the tie of the round."
Manchester United followed rival City out of the hat but was given a more forgiving draw in the shape of Olympiakos.
Club secretary John Alexander is pleased with the outcome, and says it shows the importance of finishing on top of the group: "If you look at the ties Arsenal and Manchester City got, that’s exactly why we needed to win our group. I think once we knew the five possible opponents we were quite relaxed and whoever came out of the pot would’ve been a good one for us. It’s a good omen [that United have beaten the Greek side four times out of four].
"The atmosphere over there — Manchester United are a very popular club in Greece — there will be a big United support when we go to Athens."