Brett Favre has talked in recent weeks about the fact his surgically repaired left ankle hasn't responded as well as he would like and has indicated that while he has the desire to return he won't do it unless the ankle comes around.

But during an interview Thursday afternoon on KFAN Radio, Vikings coach Brad Childress indicated he believes that Favre's decision will have to come more from the mental (not physical) aspect of can he play a 20th NFL season?

"So many of these guys know, your mind is still agile but physically your body betrays you," said Childress, who visited with Favre on Monday in Hattiesburg, Miss. "You can't do the things that you wanted to do and that's usually what drives you out and I think that's where some of that is going on. Obviously, he put all the cynics to rest last year as a 40-year-old quarterback with what he did and his mind is still agile. But it's just whether you have it mentally to keep going. Physically, I think he's in pretty good shape."

In fact, Childress said Favre was running stadium stairs while wearing a weighted vest. The Vikings coach admitted he really isn't all that concerned about Favre's ankle, which was repaired during an arthroscopic procedure in late May.

Childress, of course, went through all of this last year when he tried to talk Favre into playing after the quarterback had surgery on the torn biceps in his throwing arm. In that case, Favre called Childress a day before the Vikings reported to camp and said he was going to stay retired. Favre changed his mind and joined the Vikings on Aug. 18.