Barcelona top the group at the halfway point with three victories from their three matches, while City have four points after a draw against Celtic and victory over Borussia Moenchengladbach.
Guardiola said the group standings meant Tuesday’s match was of greater significance for City than Barcelona.
“It is not a final for them. It is a final for us,” the 45-year-old explained.
“There are just three games left. We dropped two points in Glasgow against Celtic and we need to recover those points.
“Every manager, every trainer has his plans. We know them, they know us. But football is unpredictable. Hopefully our quality in front can make a difference.
“In the first half we played well at Camp Nou but the two wide players for Barcelona are almost unstoppable. The only thing I can ask of our players is they play the way they know.”
With Bravo suspended following his red card in the first fixture, Willy Caballero will start in goal for the match at the Etihad Stadium and Guardiola has every confidence in the 35-year-old goalkeeper.
“He has helped me very much from the first few games,” Guardiola said.
“I like Willy on a personal level and as a goalkeeper he has played and given a lot of confidence. If he plays well, we’re all be happy with him. If he doesn’t, then we will support him. But I have no doubts about him.”
City forward Nolito also said striker Sergio Aguero will be a key player against Barcelona and insisted his teammates have the self-belief needed to beat the La Liga champions.
“I think he’s one of the best strikers in the world,” Nolito said. “And it’s a pride to have him in the team and we hope he has one of those days where he scores lots of goals.
“Sincerely, we have to beat Barcelona one day. We have to win this one because of the situation we’re in. We have to. Knowing how strong they are we will have to be at our best.”
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