Last month, FRONTLINE aired a documentary called League of Denial- so named because the NFL has taken no dramatic policy positions on the growing problem of debilitating head injuries.

But it’s an issue that’s not going away, as this week former Green Bay Packers quarterback Brett Farve said he, too, has had complications.

Favre spent 20 years in the NFL and estimates he's been sacked at least 500 times. Monday morning he told NBC's Matt Lauer that he shows signs of memory loss- specifically he couldn't remember his daughter playing soccer. Favre says he believes his problems stem from head injuries.

GUEST