Arsenal manager Arsene Wenger is confident troubled defender Sol Campbell will soon return to action for the Gunners.

The England defender has been given time off after a dismal display against West Ham on Wednesday, when he was substituted at half-time and promptly left Highbury.

Wenger revealed afterwards that the 31-year-old had not been mentally fit enough to carry on and Campbell has been left out of the squad to take on Birmingham on Saturday.

Teammate Robert Pires revealed that Campbell has a "big worry" in his private life, but Wenger insisted that not only would the centre-back return he would also do so in a capacity to regain the form which made him an England regular for many years.

"I don't know when I will see him - next week certainly - but I don't know when," Wenger told the Evening Standard. "I hope that when he comes back he comes back stronger. There is no reason why he can't be the same player."

Campbell's crisis has coincided with an absence of other experienced defenders through injury or international commitments.

Wenger added: "At the moment I am worried about Sol because he is down. I don't want to interfere with how he feels individually and privately. I have not seen any special problem affecting him."

Wenger also stressed it was his call - rather than the defender's - to replace Campbell with midfielder Sebastian Larsson at half-time on Wednesday night, with the young Swede having to operate as an emergency left-back.

He said: "It was my decision to change him. There is no bad feeling between us. Does he have a future at Arsenal? Of course he does."