Madrid needs to end a run of bowing out in the Champions League the last eight times they have lost the first leg, but Zidane also stressed the need for patience as an away goal for the Germans would leave Real needing four to go through.
“I am always positive, and I achieved something as a player with this philosophy,” said Zidane, who scored the winner for Real in the 2002 Champions League final.
“What most concerns me is to see the faces of my players, and they are very focused on the game, so that eases the pressure. We need to score, but we have 90 minutes or more to do so.”
Madrid’s fortunes have turned around dramatically in La Liga in recent weeks as they came from behind to end Barcelona’s 39-game unbeaten run earlier this month before closing to within four points of the leaders with six games to go after Barca lost again at Real Sociedad on Saturday.
And Zidane is hopeful the momentum of their league form will carry into a famous night at the Santiago Bernabeu, where Madrid have scored 37 goals in nine games since he took charge in January.
“The message is patience because we know anything can happen in football,” he added.
“As we’ve seen in La Liga — with Barcelona’s goal we were 13 points behind, and now we are four. That is the great thing about football.
“We have to keep our heads; we are not going to win (the tie) in 10 or 15 minutes.
“It will be much more difficult if they score a goal. Anything can happen, but we need to be concentrated from the first minute.”
Madrid will be at full strength as Karim Benzema has recovered from a knee knock that forced him off in the first leg.
Captain Sergio Ramos returns from suspension, while the likes of Gareth Bale, Toni Kroos, and Luka Modric were rested for Saturday’s 4-0 thrashing of Eibar.
“We have a great team full of talent, and I think that the whole side is capable of coming back tomorrow with the help from our fans,” said Modric.