MINNEAPOLIS -- Brett Favre has become something of a medical expert through the years, a quarterback who has minored in pain management as he has put together a streak of consecutive starts that stands among the most impressive records in all of sports.
Yet even a 41-year-old who has played 20 seasons in the league still can learn something new, and Favre is now faced with a pain and an injury that he's never felt before.
Favre sprained the sternoclavicular joint in his throwing shoulder after getting crunched by Bills linebacker Arthur Moats on Sunday, an injury that leaves the Minnesota Vikings quarterback unsure of whether he will be able to start his 298th straight regular season game next week.
"If we were talking ankles or elbows, thumbs or something like that, I would probably be a little more up to date on how to deal with it," Favre said after the Vikings beat the Bills, 38-14. "First time in 20 years I have ever done anything like that, so it is kind of surprising."
The SC joint is located where the collarbone meets the breastbone. The more common shoulder injury for athletes is an AC joint sprain. According to Harvard Health Publications, SC joint sprains occur most often "when a driver's chest strikes the steering wheel during an auto accident, or when a person is crushed by an object."
For Favre, it was the latter case.
On the third play of the game Sunday, Moats came flying off the right edge and blindsided Favre just as he was about to throw a pass. The 250-pound linebacker flattened Favre, landing on top of him as he drove the quarterback into the turf.
"He took a pretty good lick in the back as he was coming back and getting ready to throw the ball," said running back Adrian Peterson, who picked up the slack with 107 yards and three TDs. "I know that didn't feel good. I don't know the extent of his injury or what's wrong with him, but obviously for him not to come back in, it must've been painful."
Favre headed to the locker room with athletic trainer Eric Sugarman for an X-ray, which revealed no broken bones and returned to the sideline later in the second quarter.
During the game, the team called his return questionable, but Favre said there was no way he could have been effective if he had to go back in the game.
"I stayed dressed because (third-string QB) Joe Webb had pulled his hamstring," Favre said. "So in case I had to go in I could hand it off, at least with my left hand. I couldn't throw. I tried to on the sidelines."
Jackson filled in well, throwing for 187 yards, two touchdowns and three interceptions to help the Vikings (5-7) to their second straight win. Interim coach Leslie Frazier said Favre will remain the starter if he is healthy enough to play, and Favre's reputation as the NFL's ultimate iron man will be his enduring legacy, more than all the records he owns and the Super Bowl he won with Green Bay.
"Brett is going to push to play Sunday," Jackson said. "You know the type of player he is. He's played 15,000 games straight now. Probably 15,001 next week."
It's been a difficult year for Favre, who has struggled with a sore shoulder, tendinitis in his elbow, two broken bones in his ankle and 10 stitches in his chin from a hit against the New England Patriots earlier this year.
He also entered the game 30th in the NFL in passer rating, a far cry from his 33-touchdown, seven-interception performance in 2009 that helped the Vikings reach the NFC title game.
Favre has also been dogged by an NFL investigation into allegations that he sent inappropriate messages to a game-day hostess when both worked for the New York Jets in 2008.
Through it all, Favre has been in the huddle at the start of every game for the Vikings, and he made it clear that he wants that to continue if he is physically able.
"For me, I have always been willing," he said. "The reward has always been great enough. I just enjoy playing. ... I would love to finish this out, this whole year."