An official attendance of 59,563 was given but there were large sections of empty seats visible.
Asked for a message to fans, Wenger said: "Come and support the team. If you love football, you go out there and I think you see quality football.
"We can not detect exactly why everybody did not turn up."
Clubs usually count season ticket holders in official attendances whether they are actually present or not, and there were reports before Thursday night's game that as many as 2,500 fans had returned their tickets because of disillusionment at another faded Premier League title bid.
Wenger said that there was no way of knowing why any fans did not attend but defended his side's performance.
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He said: "It was a special night as well, a Thursday night, and I don't know if you are intelligent enough, nor am I, to detect exactly why everybody that did not turn up tonight did not turn up.
"I believe we dominated from the start to the last minute and in fact, was what we did in the 1-1 draw against Crystal Palace on Sunday.
"Overall I believe the quality of our game was very good. Maybe, we could have scored more goals."