Brett Favre is listed as doubtful for Minnesota's season finale against Detroit, which could also be his final NFL game. Favre has not passed his concussion tests this week. He wore his red quarterback jersey, but he didn't have a helmet on and didn't participate in any drills during Friday's practice. "I'm going to just leave it as doubtful for now, without going into any detail about it," interim coach Leslie Frazier said, adding: "If we leave him doubtful, it should cover things with him. Never rule him out."