Arsenal boss Arsene Wenger admits their chances depend on keeping Robin van Persie fit.

Van Persie struck twice in victory over Champions League opponents Borussia Dortmund last night.

"At the moment I believe that Robin is an exceptional player. He takes advantage of our offensive style from the wings. We create a lot of chances but I don't deny that at the moment he is the one who scores all the goals. We hope we can keep him fit and with us for a long time," Wenger told arsenal.com.

"What I saw in him is that he speaks his mind, he is completely focused on football and thinks day and night about the game. He is completely dedicated. It is not always obvious to put a striker as captain because he is in front of everybody. He was vice captain last year and was then captain while Fabregas was out."