Madrid will take a slight advantage into the match following a 1-0 win in the first leg last week and Guardiola is under no illusions as to the size of the task.
"They're a team that run incredibly, they are so fast. When you lose the ball you need to get back fast, but the further they are from our goal the better," he told reporters at a press conference.
"Possible we'll need to use some of our other weapons too. Of course they can attack tomorrow without a problem. A coach needs to take lots of options into account and Madrid have the qualities for that. You can already see it in the League where they are dominating. They're a great side."
Bayern are the current holders of the trophy.