Berlin - Arsenal want to put their poor start to the English Premier League season behind them as they aim to reach the group stage of the UEFA Champions League.
Arsenal slipped to a 3-1 home defeat to Aston Villa Saturday and have several injury problems ahead of Wednesday's first-leg play-off in Istanbul against Fenerbahce.
Alex Oxlade-Chamberlain and Kieran Gibbs are both set to miss the match while Bacary Sagna and Tomas Rosicky face a race to be fit.
Wenger is hopeful that Jack Wilshere will recover from playing 90 minutes at the weekend, on top of his performance for England in midweek.
And the Frenchman has to lift his side after their disapppointing opening-day defeat at home.
"It is important not to let the mood drop - after such a disappointing start that will be the difficulty," he said.
"We will bounce back because the spirit and focus in the team is good, but I don't deny that this is a massive disappointment for us."
The Gunners, who are aiming to reach the group stage for the 16th successive time, come up against a Fenerbahce side fighting to stay in European club competition following banishment by European governing body UEFA.
The ban has been temporarily lifted while Fenerbahce appeal to the Court of Arbitration for Sport in Lausanne, where a ruling is expected at least before the group stage draw next week.
The Turkish side under new coach Ersun Yanal were also on the losing side on Saturday, going down 3-2 after leading 2-0 against promoted Konyaspor in their opening Super Lig game.