It could be the end of the line for Brett Favre

Chicago's Brian Urlacher, #54, looks down at the injured Brett Favre on Monday.

Brett Favre talked his way back into the starting line-up, hoping a snowy Monday night game would be just the setting he needed.

Instead, his surprising return ended all too quickly. A head injury that Favre described as a concussion forced him out of the game and may have ended his career, too.

He shrugged off a sprained right shoulder to start the game on Monday night, receiving a thunderous ovation from the crowd when he was introduced. But the Bears defensive end Corey Wootton slammed Minnesota's 41-year-old quarterback to the ground in the second quarter, and Favre watched the rest of a 40-14 defeat from the sidelines.

Favre's helmet bounced against the frigid turf, and he stayed motionless for a few seconds before slowly rising and walking off with his head down. Favre's face was streaked with material from the artificial surface and he appeared dazed as he put on a jacket on the sideline.

He had completed five of seven passes for 63 yards with a 23-yard TD pass to Percy Harvin and an interception. Favre has said several times this year that this will be his last season, and only two games remain.

"It made a lot of sense that, if this were the last game, to play it here in front of our fans," he said.

Favre was not supposed to play at all, after being declared out on Saturday on the official injury report. But the Vikings upgraded him to questionable on Monday after he woke up feeling better and wanted to give it a try.

"I knew it was the last home game," Favre said. "This also may seem kind of crazy, but I was looking forward to playing in a blizzard."

He came out for warm-ups wearing a black ski mask, and after making some throws with flakes falling around him, he was announced as the starter. Favre had his NFL-record starts streak end at 297 games last week against the Giants.

Favre was blindsided by the Buffalo Bills linebacker Arthur Moats and drilled into the turf on his first pass of the game on December 5. He watched practice again all week, with rookie Joe Webb set to start.

But Favre cannot be counted out, especially for the high-profile Monday-night games. He has had some of his greatest performances on the NFL's biggest regular-season stage, none more notable than when he threw for 399 yards and four touchdowns in a Monday night win at Oakland one day after his father died of a heart attack.

"Brett Favre attempted to throw the football two days ago and was unable to," the Vikings trainer Eric Sugarman said Monday in a statement issued by the team.

"He declared himself out at that time. He woke up this morning feeling much improved. His symptoms and function have improved dramatically over the past 24 hours."

Favre regretted that what might have been his last game ended in another injury and another Vikings defeat. "I wish it would have turned out differently," he said.

Asked if he would play in one of the team's final two games, he said: "I don't know with this concussion, based on my decision-making, I probably shouldn't tell you one way or the other right now."

The snow tapered by kick off, but picked up again throughout the second quarter, the kind of wintry conditions Favre got to know well during 16 years with the Green Bay Packers.

The Packers were 43-6 with him at quarterback when the temperature was 1°C or colder, but his status as a cold-weather warrior has been tarnished later in his career, especially when he threw an interception in overtime that led to the Packers' defeat by the New York Giants in the NFC title game after the 2007 season.

Favre had played 61 games with the temperature at 4.4°C or colder before Monday. He had completed 61 per cent of his passes with 98 touchdowns, 64 interceptions and an 85.1 rating in those games.

However, in the 16 games under those conditions since 2005, not counting Monday's, he had completed 57.7 per cent of his passes with 11 touchdowns, 26 interceptions and a 64.1 rating. His 20th NFL season has been one of his toughest. In addition to the streak ending, Favre has 19 interceptions, third most in the league. His 69.6 quarterback rating was good for a lowly 30th before the game started.

While most of the post-game attention was on Favre, the victory meant that Jay Cutler and the Bears took the division title.

Cutler's three touchdown passes and Devin Hester's record-setting punt return helped the Bears fly past the Vikings 40-14 on a frosty, hard-hitting Monday night to clinch the NFC North.

Cutler finished the game with a big bandage on his chin to cover a gash caused by a helmet-first hit by the Vikings cornerback Antoine Winfield. Cutler said he needed three stitches.

He resembled a younger Favre after the game as he revelled in an unexpected play-off berth for a Bears team that began the season overshadowed by Favre's current and former teams.

"Just had guys going to work every day," the coach Lovie Smith said. "They don't listen to a lot of the stuff going on around them. They do everything we ask them to do as coaches, and we haven't peaked yet."