Regularly after offensive plays in the Bears' last game against the Lions, fullback Jason McKie noticed left guard Ruben Brown would return to the huddle grimacing in pain.

"Sometimes, I just thought he was mad at the play or something,'' McKie said. "You couldn't always tell that he was hurt.''

Yes, you could.

The first clue might have been the Bears owning the league's second-worst rushing offense and giving up 21 sacks at midseason. Something was wrong.

Brown's injured right shoulder that will require surgery and forced the Bears to place him on injured reserve Thursday doesn't explain everything. But it's a good start.

All that talk in NFL locker rooms about the need for five guys on the offensive line needing to work as one isn't just rhetoric. It's real. For offensive linemen, the communication, the technique all rely on working in synch with the guy planting his hand in the grass next to you.

When one part of the machine is defective, as Brown clearly was for most of the first half given his teammates' revelations Thursday, the whole machine malfunctions.

Through eight games, the Bears offensive line most certainly has malfunctioned.

"He definitely was playing hurt [all season],'' center Olin Kreutz said. "That's just the kind of guy he is. He's a warrior. He couldn't even use his arm most of the time in the fourth quarter, but he was just going anyway. I don't know if you could see him out there [but] sometimes in the fourth quarter, he would have the rest his arm on somebody. He couldn't really use it.''

Another stunning admission came from McKie.

"Sometimes, he would be in the huddle and would be rubbing his shoulder and moving his arm around,'' he said. "So I knew something was wrong with him. I knew he had some shoulder problems before, but I didn't know it was to the extent that it is now. But he stuck it out.''

That probably makes Brown one of the toughest players to ever put on the navy-and-orange uniform, and you don't make nine Pro Bowls being soft.

But his teammates' testimony also raises legitimate questions about why the Bears continued to trot out damaged goods for eight straight starts despite Brown's warrior-like mentality that would have made sitting him difficult.

If Bears players recognized how badly Brown was hurting and how it might have been affecting his performance, why didn't Bears coaches do something about it? How much of them hoping it would get better only make it worse?

Kreutz acknowledged knowing about Brown's limitations "for a while,'' and the Bears didn't just wake up Thursday and decide it was time to shut down a Hall of Fame-caliber guard whose performance was substandard. They knew.

"Whose to say what was a factor? We didn't play as well we needed to, period,'' Smith said. "For us to try to figure why and if that really mattered, it doesn't really help us right now.''

Smith talked like a guy who expected Brown to return in 2008 but that doesn't seem realistic for a team possibly two months away from starting a rebuilding project. The next time you see Brown, 35, he might be wearing a yellow blazer and giving an induction speech in Canton, a realistic possibility for a popular 9-time Pro Bowl selection.

He nearly left the game once in 2004 after a messy exit in Buffalo but came to the Bears for the chance to play alongside Kreutz. It was a good run, but hard to imagine the team bringing back a 36-year-old guard with high mileage in '08.

The Bears have to get younger on the offensive line and find out what they have in 29-year-old replacement Terrence Metcalf, to whom the Bears have committed $3.4 million for the three seasons following this one.