"I don't know when Sol will return. I have not spoken to him since Wednesday night and I don't know where he is at the moment," Arsenal manager Arsene Wenger told a news conference.

"I think he just needs a few days to clear his head but I don't know if he will be coming in on Monday. I am not worried."

The centre back is on compassionate leave after his shock halftime substitution during Wednesday's 3-2 home defeat by West Ham.

Wenger said then that Campbell felt guilty at being responsible for West Ham's two first half goals and was not mentally up to playing the second half.

Arsenal team mate Robert Pires was quoted in British newspapers on Friday as saying Campbell had an unspecified personal problem. Wenger says he has no clue what lies at the root of his defender's problems.

"I have no news - frankly and sincerely I do not know what it is. But it is not a big concern for me, he just needs a break.

"He is just in a difficult period but you can only help people if they are in touch.

"He is a guy I rate highly as a human being. Every human being has the right to privacy and you try to respect that.

"The only you can do is accept that every human being reacts differently to problems. The only thing we can do as a club is support people when they need our help.

"When the players come out with their private life you try to support them, but you have to respect that some don't like it."