The 25-year-old came in for criticism following Tuesday's loss in the UEFA Champions League, with former Germany captain Michael Ballack describing his performance as "lacklustre".
But ahead of Saturday's trip to Aston Villa, Wenger has come out in defence of Ozil, urging patience with Arsenal's club-record signing as he looks to regain full fitness following Germany's successful World Cup campaign.
Ozil started all seven games for his country in Brazil, and Wenger believes his exertions at the tournament have affected his early-season form for Arsenal.
"The criticism is unfair because it's post-World Cup," Wenger told a news conference on Friday. "It takes a few months for them to get back to their best.
"Fans need to be patient. You want your best players in every game but you have to be united and go through hard periods.
"Why should Ozil be a scapegoat? We've lost one game since April 1. We had very difficult games against teams like Besiktas.
"Everybody judges players on one game but football is played with many ups and downs."
Wenger also revealed Calum Chambers, Mathieu Flamini and Jack Wilshere will all be available for the trip to Villa Park, while Arsenal wait on news regarding Mathieu Debuchy's ankle injury.
The French full-back, who suffered the problem against Manchester City last week, will undergo an examination later on Friday to determine whether he will need surgery.
