While the Gunners head into the first leg on the back of Saturday's deflating 1-0 home FA Cup defeat by Blackburn, and currently only fifth in the Barclays Premier League, Bayern look in ominous form.
Jupp Heynckes' men, runners-up to Chelsea in the Champions League final last season, are 15 points clear at the top of the Bundesliga, keeping seven clean sheets in the last eight.
Wenger, though, expects his team to rise above the negative headlines.
"What is important is that we focus on the quality of our game, that we play at our best and play with belief," said Wenger, who must do without full-back Nacho Monreal tonight, the Spain international is cup-tied following his deadline-day transfer from Malaga.
"We have to put it in our head that we have 180 minutes to qualify and not to rush our game.
"If I listen to the questions, we are not favourites but I trust our quality, our spirit and our mental strength.
"We must play with a positive mentality, it is important you believe you have a good chance."
Wenger accepts Arsenal must give themselves something to take back to the Allianz Arena next month, especially given their poor general record away from home in the Champions League.
"It is vital because 0-0 at home is a very good result in the Champions League knockout stages, but of course we will try to score goals," he said.
"However, 0-0 is not a disaster at home, but we are a team who are offensive and we will try to go forward."
Following their unexpected defeat to Blackburn, just over two months after crashing out of the Capital One Cup on penalties against League Two Bradford, the Gunners now look set for another trophyless campaign – unless they can pull off a shock of their own.
Wenger said: "In Europe you face some teams with quality – Barcelona, Real Madrid, but they don't win it every year.
"We have consistently been in the quarter-final, semi-finals and also once the final, now we want to break through."