"He played with authority. We know his talent and I'm very happy with his performance," Wenger told Arsenal Player.
"He has changed a lot, there has been a complete mental transformation in Lukasz's attitude. He is more vocal, has more authority and mentally he absorbs the pressure of the game much better.
"He has a huge talent, which we know all about. Sometimes to go out of the game for a while helps people to mature and think about their own game. If they really want to become a better player, they think, 'How can I become better'.
"I think it is a combination of both [working with him and his own maturity] but I would give him 90 per cent of the credit. He works on all the aspects of his game."