Lauren has been out for 11 months with a knee injury.
Wenger said: “It is nice just to have him back.
“If you think what Lauren has gone through recently, the strength of character this guy has shown is amazing. And when you are at a big club that is the first quality that you need.
“There was a question mark about [his future] I must honestly say. But his desire, his strength and the way he practiced and worked so hard during his rehabilitation was top, top class. But I am not surprised. I know him and I brought him here. Lauren is an exceptional human being. That is why he came back.
“It is great to have such an experienced player and such a winner with us again. When you have him in the side then you always have a chance.”
