The Arsenal captain, Thomas Vermaelen, is struggling for confidence, manager Arsène Wenger has admitted ahead of a run of games he described as "massive".
Vermaelen has had a difficult start to the season, with another high-profile error costing Arsenal the opening goal in last Saturday's disappointing 2-1 defeat at Manchester United. Wenger explained his problems are more mental than physical.
"Physically he is outstanding," said Wenger, "I think what has happened to him in recent weeks has affected his confidence. Overall physically he has no problem."
Wenger suggested the captaincy, which Vermaelen inherited when Robin van Persie left, is a weight to bear. "You put more pressure on yourself when you are the captain," said Wenger.
"You want to be the best player in the team. You cannot be a defender and not make a mistake. But if you make one then maybe you put a bit more pressure on yourself."
Arsenal host Fulham today before playing Tottenham, Montpellier, Aston Villa and Everton this month.