Don't believe Brett Favre is finally retiring?

Well, the NFL's all-time leader in almost every major passing category at least has filled out the forms.

Favre made another move toward leaving the game for good by filing retirement papers with the league, NFL spokesman Greg Aiello confirmed Monday.

This is merely a procedural matter, to start the clock on a player's pension and Hall of Fame eligibility. It's worth noting, too, that Favre has done this before, only to change his mind. Retired players can request to be reinstated at any time.

But the news, first reported by Fox Sports on its website, was another sign that Favre's thrill-filled 20-year career has come to an end, as he repeatedly insisted throughout a painfully disappointing 2010 season for the Minnesota Vikings.

"All indications, when I talk with him, and we've had many, many discussions -- this is it," new Vikings coach Leslie Frazier said after the season. "I don't even think it'll be an issue in the future. I don't see any situation that's going to change his mind. You might say, 'We'll, we've been down that road before,' but it's different now. Things are different, in his life and in the organization's life as well."

Favre, 41, threw for just 11 touchdowns in 13 games and was intercepted 19 times, finishing with a career-low 69.9 passer rating that ranked third-worst in the NFL among qualifying quarterbacks.

Favre's body took quite a beating, and he was knocked out of three different games while dealing with injuries to his elbow, foot, chin, neck, back, ribs and calf -- plus the sprained throwing shoulder that ended his NFL-record streak of 297 consecutive regular-season starts. Then Favre suffered a concussion in what wound up being his last game, Dec. 20 against the Chicago Bears.

"I know it's time, and that's OK. It is," Favre said after the season finale. "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."

After years of waffling, Favre cried as he announced his retirement from the Green Bay Packers in March 2008. With the Vikings interested, but the Packers unwilling to let him join their NFC North rivals, he was traded to the New York Jets.

Following one season in New York, Favre declared he was done again in February 2009. The Vikings wooed him back to the field that summer, and they rode his renaissance performance -- 33 touchdowns and only seven interceptions -- to the NFC Championship Game.

But after needing another summer of persuasion to return in 2010, Favre wasn't the same, and the Vikings slumped badly to 6-10 while going through all kinds of drama, including coach Brad Childress' midseason firing.

Favre was fined $50,000 by the NFL for failure to cooperate with a league investigation into allegations that he sent lewd photos and messages to a team employee when both worked for the Jets in 2008. Also, Favre's short-lived union with wide receiver Randy Moss was a spectacular failure, and the Metrodome roof collapsed late in the season, forcing the team to play December "home" games in Detroit and the University of Minnesota's outdoor stadium.

"It's been a wonderful experience for me," Favre insisted after the season finale. "This year did not work out the way we would have hoped, but that's football. I don't regret coming back. I enjoyed my experience here."

Now Favre has headed home to Mississippi, presumably for good as his two-year contract with the Vikings expires. Favre's official website even sent out a marketing e-mail blast over the weekend, advertising a "Thanks for the Memories" poster for sale. A portion of the proceeds go to the Favre 4 Hope Foundation, which helps disadvantaged and disabled children and breast cancer patients.

The Associated Press contributed to this report.