BALTIMORE — Stuck in a brawl against one of the NFL’s biggest, baddest bullies, Denver blinked. Now how are the Broncos going to look themselves in the mirror?

Denver got trounced 31-17 by Baltimore. Worse, the Broncos were manhandled. Even in the 21st century, sometimes football comes down to down-and-dirty essentials, where what matters most is unbridled tes-tosterone and brute strength.

When the game got raw Sunday, the Broncos backed down.

“We got our (tails) kicked pretty good,” Denver cornerback Champ Bailey said.

The bullying began early and thumped the Broncos hard. It started when Baltimore fullback Le’Ron McClain, who plays an old-school position with the passion of an angry bowling ball, rocked the world of Broncos linebacker Jason Hunter, who wears No. 52 for Denver.

With a sly grin, McClain recalled: “I was telling No. 52 after he hit me one time and we rocked a little bit: ‘Man, you’ve got to deal with that all game. Four quarters of that. Banging on every play.’ “

In response to the repeated body blows, the Broncos lost heart. If this were a fight, a referee would have stepped in and stopped the mauling for fear of permanent injury to battered Denver egos.

“It’s huge to look into a guy’s eye in the fourth quarter and know he’s tired. We’ve got him. We’ve worn him out,” McClain said.

Baltimore is as mean as the scowl etched on the face of ferocious linebacker Ray Lewis. This is a toughness rookie tight end Ed Dickson reverently calls the Ravens’ Way. It’s built on a rock ’em, sock ’em attitude that he quickly discovered rattles bones even when players are practicing without pads in the spring.

While Broncos coach Josh McDaniels has vowed to build a physically intimidating team, his words ring as empty as the meekness of Denver’s inept running game and his promise has been betrayed by a defense whose primary alignment against the Ravens seemed to be the fetal position.

“For the first time,” McDaniels admitted, “I thought our mental toughness was questioned.”

Last season, after being beaten to a pulp at Baltimore, an undefeated Broncos team fell apart. So the ugly question hovers like a dark cloud: Is Denver tough enough?

We know safety Brian Dawkins is as prickly as barbed wire rusted and hardened by 36 winters. But, in the absence of injured pass rusher Elvis Dumervil, does the Denver defense truly scare anybody?

Bill Romanowski, who gave those championship teams from the 1990s their nasty streak, quite frankly doubts it.

“When you really have it as a defensive player, it’s a sick, dark place you go to,” he told me Friday, when accurately predicting the pain Denver was doomed to experience against the Ravens.

The Broncos were outgained on the ground 233-39. After watching them get shattered at the line of scrimmage, how haunting do Romo’s words of warning read now?

“Ray Lewis is going to go to a really dark place against the Broncos,” Romanowski said 48 hours before kickoff. “I don’t know how many Broncos have got that really dark mentality on defense. Dawkins? I would say yes. But I don’t think there’s enough (players) that want to go to a really, really dark place.”

So, with their record at 2-3 and the season at a crossroads, what are the Broncos going to do now? Complain the other team plays too rough? When sacked six times at Tennessee a week ago, Broncos quarterback Kyle Orton called out Titans cornerback Courtland Finnegan for being cheap and dirty.

It was ill-advised to complain, suggested Romanowski, because the Ravens could look at the QB and decide: “Orton’s a crybaby.”

Playoff berths are seldom rewarded for whining. The cruel aspect of football is that the trenches allow nowhere to hide. There are no peace negotiations in the trenches.

“You know when you’ve got a guy, and you know when you don’t,” said McClain, the Pro Bowl fullback for Baltimore. “I had ’em on this day.”

How obvious was the physical domination by Lewis and his Baltimore defense?

“It’s simple. The scoreboard don’t lie,” Lewis said.

The Broncos must look in the mirror and ask a simple, brutal question: Are they tough enough?

Mark Kiszla: 303-954-1053 or mkiszla@denverpost.com