It was the eighth red card Xhaka has received in two and a half years at Arsenal and Borussia Monchengladbach.
When it was put to him that eight red cards in such a short space of time suggested Xhaka had a disciplinary problem, Wenger replied: "It is one. We are not responsible for the red cards he got somewhere else.
"He made a foul that could have got him a yellow card, that could have got him a red card. It was not meant to hurt anybody. It was just a late tackle to stop a counter attack that has been punished.
"I feel that he is intelligent enough to analyse that."