Minnesota Vikings quarterback Brett Favre officially filed his retirement papers on Monday.
In November, Favre told former NFL coach Steve Mariucci on the NFL Network that he will not be returning to play in 2011.
After sitting out in the season finale against the Detroit Lions due to a concussion, Favre said "it's time" in a postgame retirement speech.
"I know it's time, and that's OK. It is," the 41-year-old said. "Again, I hold no regrets, and I can't think of too many players offhand that can walk away and say that. Individually and from a team standpoint, it was way more than I ever dreamed of."
Favre retired in 2008 with the Green Bay Packers and in 2009 with the New York Jets, only to return both times.