Martino wants opening goal
The two sides have played four times this season in three separate competitions, and each time the match has ended in a draw.
Barca have not been in front in any of those games, with Diego's spectacular opener in the first leg at Camp Nou last week being cancelled out by Neymar's equaliser.
Martino wants to buck that trend in Wednesday's second leg, and believes an early goal for his side will change the complexion of the tie.
"We haven't been leading at any point and that's very important," he said.
"We need to score at least one goal tomorrow and let's see if we can create the scenario of us leading and try and 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."
Midfielder Cesc Fabregas, meanwhile, called on his team-mates to play with the club's identity in mind, and to be careful of Atleti's threat on the counter attack.
"We have to be Barca at our very best," he said. "They have a very defined style of play and we need to find a way of neutralising it with our own strengths.
"We need to be careful with our passing because we know they have quick players.
"We're not scared but we need to make sure we don't panic. We need to be brave."