The Catalan giants are trailing in the semi-final tie 4-0 from the first leg played at the Allianz Arena in Munich last week.
"I expect that we will be ourselves, that we will try to be better than Bayern," he told reporters on Tuesday. "We know we have to score, I know we can do that. We should be ourselves - that is the important thing. Scoring goals but also playing good football. It is very obvious we cannot concede, it will make it that much harder. But we have to get goals as well.
"The players are aware of the difficulty of the match. We are FC Barcelona and we cannot take this tie for being lost already. If we do not make it, we have to hold our heads high, fight until the end, and have our fans feel proud about us.
"We know we need the fans. It is not the same to have a quiet stadium compared to a stadium full of people cheering. Bayern had everyone cheering for them and that helped them without a doubt. But we cannot always ask the fans for help, we also have to give them something back in return."
Barcelona last won the Champions League in 2011.