Wenger is happy with the progress of both defenders, and believes their hard work before the season started has been key.
"This year they have benefited from the fact they had a good preparation," he told arsenal.com.
"Carl has as well gained one year's experience compared to last season. He came from Charlton and was straight away thrown into the Champions League. You can say that from game to game now he grows because it is linked with confidence.
"You need first to know that you belong there. Once you know that you can express yourself and then you see that in every game there is more coming out of him."