UPDATE: Favre speaks of being 'tired mentally'
ESPN.com reporter Chris Mortensen wrote that he received a voice message from quarterback Brett Favre explaining that his decision to retire was based on his unwillingness to prepare for a season that he couldn't be assured would end in a Super Bowl victory.
According to Mortensen, Favre acknowledged that he felt he could play another year.
"I know I can still play, but it's like I told my wife, I'm just tired mentally. I'm just tired," Favre said.
"If I felt like coming back -- and Deanna (his wife) and I talked about this -- the only way for me to be successful would be to win a Super Bowl. To go to the Super Bowl and lose, would almost be worse than anything else. Anything less than a Super Bowl win would be unsuccessful," Favre said in the message.
"I know it shouldn't feel unsuccessful, but the only way to come back and make that be the right decision would be to come back and win a Super Bowl and honestly the odds of that, they're tough. Those are big shoes for me to fill, and I guess it was a challenge I wasn't up for. "