Wenger said: “The future is very promising when you see what he is delivering now. It looks like from game to game he takes more responsibility and he is improving.
“He was out for a year so I don’t think he is at the best of his game. Also he only had a short experience in the league and he is still a little bit short physically. There is a lot more to come, but what he is doing now is outstanding.
“I am convinced Ashley Cole would have said that as well. Ashley Cole knew there was a left-back behind him who was outstanding. For a while we could accommodate the two but in the long term it is much more difficult. He could be as good.
“The only difference is that Ashley Cole is proven. I think Gael can get to the level that Ashley Cole is at the moment, but Ashley Cole has done it and Gael has it all to do. However, I believe that his mental strength and quality will allow him to get there.”