It was Wilshere's first start in almost 18 months.
Mertesacker said, "It was very good to have him back out there.
"You can see that he's getting more comfortable with his position now. He's brave now and he trusts his body. That's the most important thing, that he's capable of playing 90 minutes. He will just grow with that and he was vocal as well, which was important for us, especially at the end.
"He kept the ball well in tight situations and to come out of that is vintage Jack. That's what we want to see from him in the future here at Arsenal."