Vermaelen was slammed for making a mistake which led to Robin van Persieâs opener at Manchester United.
Wenger admitted: âThe error of Vermaelen was unwelcome. The big defenders donât make those errors.â
Ironically, Vermaelen has taken over the Arsenal captaincy from Van Persie and Wenger believes the new role has been a factor in the playerâs poor form.
The manager added: âYou put more pressure on yourself when you are the captain.
âYou want to be the best player in the team. But you cannot be a defender and not make a mistake.
âHe is a guy who is completely involved in the game, he breathes his football from morning until night. He thinks about it and wants to do well.
âPhysically he is outstanding. I think what has happened to him in recent weeks has affected his confidence. Overall, physically, he has no problem.â