The Gunners were booed off after they lost 3-1 at home to an industrious Villa side, who were helped somewhat by a controversial second-half penalty which was swiftly followed by the dismissal of defender Laurent Koscielny for a second yellow card.
Given the criticism for failing to land any major summer transfer targets despite having millions in the bank, it was hardly the ideal warm-up ahead of Tuesday night's first leg of a crucial Champions League play-off against Fenerbahce at the intimidating Sukru Saracoglu stadium - where Arsenal could well be without defenders Kieran Gibbs and Bacary Sagna as well as England midfielder Alex Oxlade-Chamberlain, who all went off on Saturday.
Wenger, though, challenged his players to show their strength of character and produce the required response in Istanbul.
"The next game becomes very important when you come out of a game like that," the Arsenal manager said.
"You must not let the disappointment gain in the spirit of the players.
"The resolute attitude we had against Villa we have to keep and bounce back on Wednesday, that is what it is about."