Wenger has paid tribute to the midfielder.
"He is a very conscientious guy. You should see how he works, how he is focused every day, because when a guy suffers as much as he did he becomes very professional, very rigorous.
"You have some guys who can drink five beers, come to training, and play and go home and nothing happens to them. And you have other guys who have to look after everything. They become very professional very early in life. And he has always been very conscientious.
"Diaby has a very serious life, he doesn't drink, doesn't smoke, doesn't go out, and is very conscientious in training. So you always feel sorry for him, so you always touch wood it will go well for him. Honestly, what he has gone through is unbelievable."