Wenger is delighted with the 26-year-old, and says he has overcome a number of obstacles to establish himself at the Club.
"There are many factors," the manager told arsenal.com. "The first one is that I believe physically he worked very hard when he arrived here. The intensity of the games took a lot out of him.
"The second problem was a bit [to do with an] understanding with his partners.
"The third problem was level of confidence. When you come to a club like Arsenal, you're surrounded by big names. It takes you a while to think 'OK I belong in this world' and he has shown that on that level he has gained a lot."