SAN DIEGO - Winning locker rooms, even those as cramped and stinky as the one buried in the belly of Qualcomm Stadium, are supposed to be a happy place.
The Broncos' locker room usually is a winning one, a happy place. But after Sunday's 28-20 win against the Chargers, only one joke was heard.
"He was on the ground? He was hurt?" defensive tackle Derek Wolfe said of the ultimate quarterback, Peyton Manning. "Oh, I didn't notice it."
The punch line came and went without a laugh track.
"Yeah, I noticed," Wolfe added. "I don't like that. It's not fun."
Near the border of Baja California, this was no bueno: Manning, the shoo-in MVP in the midst of his greatest season, down on the field, grimacing.
You probably were, too, since there's only one scenario in which the Broncos are not the favorite to represent the AFC in Super Bowl XLVIII.
It's that one, Manning on the field, grimacing.
Manning is injured. Either he was injured against the Chargers, or he was injured prior to Sunday and a pair of clean, football hits aggravated the injury.
"I'm pretty sore," said Manning, who added he would undergo an MRI on Monday.
Is it the right ankle?
"Lower body" is all he revealed.
If a man can look achy, Manning looked achy.
"I feel like the injury report is very revealing to the other opponents, as well as the folks in Vegas," he said.
OK, so that was another joke. Still, nobody's laughing.
Professional athletes are a confident lot. John Fox's catchy "Next Man Up" mantra is a good one to play by.
Manning is the exception. There is no next man to replace him. If he were to miss any time, the Broncos probably would look something like the Packers without Aaron Rodgers on Sunday. The Packers were smacked, 27-13, by the Eagles.
This lower-body issue is a big-picture issue because of what's coming next: Kansas City and its relentless, ravaging pass rush. The Chiefs lead the NFL in sacks.
The Chiefs also lead the AFC West, a dizzying fact given the Broncos' brilliance thus far.
The Broncos are better than the Chiefs, who seem to stick a voodoo doll and slip past Cleveland, Buffalo, CSU-Pueblo and Manitou Springs High on Sundays.
But the Broncos are not better than the Chiefs if Peyton is not Peyton.
"I certainly plan on (playing next Sunday)," Manning said.
On a sun-soaked Sunday made for surfing, Broncos fans turned Qualcomm into Mile High West (Coast). The lower bowl was painted orange, mainly with No. 18 jerseys. At least 30 percent of the crowd was pro-Peyton and pro-Broncos.
He put on a show, again, throwing four touchdowns, and the Broncos kicked it into cruise control. I saw vanilla play-calling, as if the Broncos didn't want to reveal more of their playbook to the first-place Chiefs. Kansas City was watching at home, on a bye week.
The Broncos limped to the finish.
Manning limped to the locker room.
"The one injury I was told about was Nate Irving with a shoulder," interim coach Jack Del Rio said, playing coy.
When the Colts beat the Broncos, they had a sack-fumble on Manning that turned the game. When the Chargers tested the Broncos, they had a sack-fumble on Manning that turned the game. What is the Chiefs' M.O.?
Sacks and fumble recoveries. They have 36 and 11, respectively.
"I hate those fumbles," Manning said. "A lot of them have been while I'm throwing."
The Broncos' secret is no secret:
Protect Peyton. Win games.
That goes for games against division rivals or in practice against friendly teammates.
"I tell our O-lineman in practice, 'I'm not trying to get a sack in practice. That's not going to be good for me or you,'" defensive tackle Terrance Knighton told me late Sunday. "We're cautious on his follow-through, not to let his hand hit our helmets. We've got to take care of each other."
You are not alone. When Peyton hits the turf, the gasp spans several states and the Broncos' sideline.
"I get nervous every time he hits the ground, whether it's practice or in a game," Knighton said. "It can be anything. He could be walking down the street and fall, and we hold our breath."
Wrap him in bubble tape. Smother him in a security detail. Find a magic wand and cure Ryan Clady's bum foot.
To survive all the way to the Super Bowl, the Broncos need to follow their own golden rule:
They must protect this quarterback.