James Harrison and the Steelers’ defense have allowed less than 300 yards 10 times this season while allowing just 14.2 points per game. (Don Wright/Associated Press)

Nearly nothing about this city says flash and panache. The span over the Monongahela River closest to the Pittsburgh Steelers’ training facility is called the Hot Metal Bridge. The sandwiches at Primanti Bros. are automatically piled high with tomatoes, cole slaw and French fries. The signature dish is the pierogi, Eastern European comfort food of unleavened dough, maybe some potatoes and onions and sauerkraut or ground meat. Basic stuff.

And the identity of the football team, the black-and-gold pride of the town, is defense. It was decades ago, when the steel mills still fueled this town. And it is now, as the Steelers begin their latest playoff drive with an AFC wild-card game Sunday at Denver.

In a season which produced four of the top six passing yardage totals of all-time — 20,682 yards from the right arms of Drew Brees, Tom Brady, Eli Manning and Matthew Stafford alone — the Steelers were left to stand up for the integrity of defensive football. They led the NFL in fewest yards allowed (271.8 per game), points allowed (14.2 per game) and passing yards (171.9 per game). And they did so with inconsistent participation from two of their best players, linebackers James Harrison and LaMarr Woodley, who played together only four times because of various injuries and Harrison’s suspension for an illegal hit against Cleveland.

“We have a saying around here: The standard is the standard,” said veteran defensive lineman Brett Keisel. “We don’t waver much from it. We expect to play well, regardless of who’s out there. That’s just the way it is.”

But as professional football has developed rules designed to protect players from dangerous hits, and subsequently favored the offense, no team in the league has had to monitor and adjust the way it plays more than the Steelers. Harrison’s one-game suspension resulted from his accumulated illegal hits, a development that has occasionally caused him to rage against the NFL. The discussion — what’s legal, what’s not, what’s football and what’s hazardous — has spread throughout the league for the better part of two years. Nowhere has it been more discussed than in Pittsburgh, right in the Steelers’ locker room.

“For a guy like myself that’s a safety, my job is to get the ball away from the wide receiver,” said safety Ryan Mundy, who will start in place of veteran Ryan Clark against the Broncos. “And sometimes, they call these hits so close. They’re like, ‘You didn’t give him a chance to prepare to get hit.’ But that’s ridiculous. My job is to not let him catch the ball. These bang-bang plays, they’re extremely tough as a defender.”

No one is more aware of that than Harrison, the undersized force who went undrafted out of college, was cut four times — three times by the Steelers, once by rival Baltimore — and rose to become the NFL’s defensive player of the year in 2008. In 2010, he was fined $75,000 for a pair of hits in the same game against Cleveland. This year, the hit on Browns quarterback Colt McCoy was his fifth over a three-year period, resulting in the suspension. At various points, has threatened to retire and railed, in an interview with Men’s Journal, against NFL Commissioner Roger Goodell.

“He’s not going to be happy about it,” Keisel said. “It’s frustrating for him. It’s frustrating for a lot of us.”

What has not been frustrating is the unit’s performance through all this. In Week 1, when the Pittsburgh offense turned the ball over seven times, the defense allowed 385 yards and 35 points in a humiliating loss to Baltimore, the eventual AFC North champ. The Steelers, though, never allowed that many yards or points again. Ten times, they surrendered opponents fewer than 300 total yards, and only once gave up more than 20 points.

“We’ve been around long enough to know that one game is not a season,” said veteran coordinator Dick LeBeau, Pittsburgh’s defensive sage. “We always just kind of let things sort themselves out.”

Part of sorting themselves out this year has been getting healthy. Woodley, who plays the left outside linebacker spot in the Steelers’ blitzing 3-4, has played only twice since October because of lingering hamstring problems. missed most of October with an eye issue. Including Troy Polamalu, the compass for the Steelers’ defense, LeBeau will have the versatility to which he has become accustomed.

“It’s probably safe to say that all 11 starters have a blitz where they’re the ones coming,” Denver quarterback Tim Tebow told reporters this week. “You have to be aware, and you have to know where they’re coming from. . . . Sometimes it looks like it’s chaos out there, but they know where they’re going and they’re going there fast.”

They’re going there fast, and they’re coming hard. As Mundy said, “You’ve got to adjust to the rules,” and Coach Mike Tomlin has said that time and again when addressing Harrison’s issues. Yet how football is played, and how it should be played, is clearly a lingering issue in the Steelers’ locker room.

“It kind of goes against how we’ve been brought up to play,” Mundy said.

The expected stars of these playoffs — Brees, Brady and Aaron Rodgers among them — are all quarterbacks, all men around whom the game revolves. In Pittsburgh, though, defense still matters, and figuring out how to play Pittsburgh-style defense within the confines of the modern game will have an impact on this postseason.

“It’s a different game these days,” Keisel said. “You really have to be cautious on where you’re hitting players. Even the smallest thing: if someone jumps up and you make that helmet to helmet, the referee can be obligated to make that call. It’s a fine line.”