The Spanish duo go into the second leg level at 1-1 following last week's encounter at the Camp Nou.
"We haven't been leading at any point and that's very important," Martino is quoted as saying by Goal.com. "We need to score at least one goal tomorrow and let's see if we can create the scenario of us leading and try to manage the game from there on.
"That's just how the games have worked out. We could have scored first in those games but we didn't. I really think that we have to go into this game and keep our intensity up for the full 90 minutes.
"We know if we go a goal up we can play a different game to the ones we have seen in the previous cases."