Arsene Wenger's side face a mountain to climb in the Allianz Arena next Tuesday after slipping to a 2-0 first-leg defeat at the Emirates last month.
The Gunners could have taken the lead in the opener but Mesut Ozil saw his penalty saved and they were then made to pay when Toni Kroos and substitute Thomas Muller scored second-half goals for Bayern.
Podolski believes Wenger's side can get a result in Germany - just as they did at the same stage of this competition last year, when the Gunners won 2-0 but ultimately lost on away goals - but he admits the first goal will be key.
The Germany forward told gwizdek24.se.pl: "It is normal that no one believes in us, when we lost 2-0 at home.
"We, the players, we're going after the qualification. We have to play as good as we did in the first 15 minutes of the first game.
"The main thing is to score a goal in the first half. Then everything will be possible."