"Brett Favre isn't messing around this time.

He's finished playing football. For good.

We think.

Two sources told FOXSports.com on Monday that Favre has already filed his retirement papers with the NFL, just weeks after the end of his 20th season.

While he could still change his mind like in the 2008 and 2009 offseasons, there is no indication Favre will return. The 41-year-old quarterback stated 2010 was his final season after rejoining the Vikings in August and reiterated that intent throughout an injury-plagued campaign.

Favre's NFL-record string of 297 consecutive regular-season starts was broken last month when he was forced to miss a mid-December game against the New York Giants because of a shoulder injury. Favre returned the following week against Chicago but suffered a concussion that sidelined him for Minnesota's final two contests."