The 24-year-old Switzerland international arrived at the Emirates Stadium last summer as Wenger shelled out in excess of £30million to prise him away from Borussia Monchengladbach.
Despite such a fee, Xhaka found himself in and out of the Arsenal side at the beginning of the season and had only started four games before October.
The former Basel youngster came with a reputation for collecting red cards and was given his marching orders by referee Jon Moss in the 3-2 win over Swansea later that month.
Xhaka established himself in Wenger's side over the Christmas period before another sending-off against Burnley on January 22 saw him become most sent-off player in Europe's top five leagues since the start of last season - having racked up nine red cards in three years.
Although there have been no dismissals since, Wenger admitted he is concerned about Xhaka being a marked man after seeing him cautioned in each of his last five games.
"I believe that he is now in a position where on the first foul he gets a yellow card. For example on Saturday (against Lincoln) - first foul, soft yellow card," the Arsenal boss said.
"So he is a victim a little bit of his reputation. You see tackles of some players who are much worse than what he did who don't even get a yellow card and he got a straight red and because he had a history of that in Germany I think he is a bit of a victim of that.
"Overall he is quite in a positive way, he masters himself much better. He was maybe a little bit before looking too much to impress but overall he has to stay on this ground because it is tackling that can get him sent off. When he defends well, staying on his feet he is a fair player."