For all the concern over Jay Cutler's health and well-being, it is the fitness of the defense that gives pause to any talk of a serious playoff run.
There weren't many sellers when the Bears were stripping the football at a ridiculous pace, but buying in meant you had to believe Charles Tillman and friends would take the ball away four or five times a game.
It doesn't in any way detract from the skill it takes to steal the football, but it did distract from the age and performance of a banged-up defense, especially against vastly inferior opponents.
The Bears have balked at that notion all season -- to the point of being offended by any suggestion of the sort -- but it is the defense that now gives offense.
Nothing was more pungent Sunday afternoon at Soldier Field when the Bears lost to Seattle 23-17 in overtime, and no member of the defense was proud of the odor.
"That was shocking," said defensive back Kelvin Hayden. "We're going to have to look at the film and straighten it out fast."
While no locker room smells pleasant after a game, for a change it was the offense holding its collective nose.
"We didn't get it done," Hayden said. "The offense bailed us out and then we let it happen again."
Up 14-10, Bears punter Adam Podlesh pinned the Seahawks down on their own 3 with 3:40 left in the game.
Game over, right?
This is the vaunted Bears defense against a rookie quarterback, Russell Wilson, who isn't tall enough to see over his own offensive line. But like a 10-year veteran, Wilson walked the Seahawks down the field in 12 plays for the go-ahead touchdown, converting once on third down and once on fourth.
"He got out of the pocket a couple times and we missed a lot of tackles," said safety Major Wright. "We've got to make tackles."
With only 24 seconds left in the game, Cutler did what he does best. He kept a play alive with his feet and found Brandon Marshall for 56 yards, a classic drawn up on the playground, and nothing new for Cutler and Marshall.
"I told Brandon to run as fast as he could down there and I'll throw it to you and you make a play," Cutler said. "I tried to buy some time in the pocket, bounced around a little bit, and found him. I put it up and he did a great job coming back for it."
The catch put Robbie Gould in a position to tie the game as time ran out in regulation, and it felt again like the Bears would escape.
But Seattle won the toss in overtime, and Wilson again took his team 12 plays down the field for a touchdown, this time for 80 yards, including 3 third-down conversions.
"I think it's surprising," Cutler said of the defense being unable to get off the field. "Our defense takes a lot of pride in that."
Brian Urlacher, Tim Jennings and Chris Conte were among the starters who watched the ending from the sidelines; Jennings after getting run over by Seattle running back Michael Robinson, Conte sick and Urlacher wrapped in ice.
Lovie Smith said Urlacher was out with a hamstring and Jennings with a shoulder. Whatever the nature of their injuries, and considering Tillman (ankle) and Lance Briggs (ankle) were slowed to some degree, the Bears looked old and sluggish on a defense that before the season was forecast to be old and sluggish.
"I've been watching some of them," Wilson said, "for 10 or 15 years."
Wilson didn't mean to give offense, but some of them really have been around that long.
"I still think we have a great defense here," Hayden said. "We just can't keep doing the things we did today. We have to clean it up."
Much will be made of Lovie Smith's decision early in the second quarter to pass up points, and rightly so, especially in light of the offensive line being the offensive line.
"That's on us," said Roberto Garza. "It's a couple inches and we have to get that. We didn't do enough to win the game."
Against a strong Seattle defense, the Bears offense actually did just enough to win the game, but the defense allowed two very long drives at the end of regulation and in overtime, and that's why they lost.
"We're better than that," Wright said. "This is a tough one to swallow."
Once again, it's worth remembering that world did not end Sunday. There are four games remaining, and three are quite winnable.
The Bears (8-4) will need at least two of them to reach the postseason, but having lost three of four there are questions being asked of a team that hasn't provided many answers in the last month.
"There's a big run coming and we have to be ready for it," Hayden said. "We will be ready. I still see us as a playoff team."
Making the playoffs is one thing. Making a long playoff run is hard to envision as injuries mount and age takes its toll.
But no one takes more joy in bouncing back and sticking it to the critics than this Bears squad.
A defeat like Sunday's provides them all the opportunity they could imagine.
•Hear Barry Rozner on WSCR 670-AM and follow him @BarryRozner on Twitter.