As time stood still, and players and coaches and fans alike all tried to process what they had just seen, the one thing that Steelers offensive lineman Ramon Foster couldn’t understand was how such a frightening moment could be borne out of something so ordinary.

The tackle in the Dec. 4 game against the Bengals was hardly any different from the 202 that Ryan Shazier had made in his four years in the NFL.

Shazier made his presnap reads, motioned out calls to his teammates, spotted Cincinnati rookie receiver Josh Malone running a short route across the middle of the field and lowered his head to meet Malone with a tackle as soon as Bengals quarterback Andy Dalton delivered the football.

“He was just doing his job,’’ Foster said.

From the moment Shazier made impact, every sense of normalcy was gone.

His body went stiff. He reached for his back. He rolled over to face the sky and squeezed his right hand as if he were checking to make sure he still had feeling in it.

Within moments, he was surrounded by team trainers. Not long after that, he was strapped to a spine board and carted off the field into an ambulance.

The air in Paul Brown Stadium went with him.

Foster has been in the league for nine years, but this was one of the rare sights, he said, that made him fear football.

The eye-blink, life-altering moment every player knows is possible but never imagines happening.

“The reason I said that it scares me is because I saw a guy making a routine play and it could potentially be life changing,’’ Foster said. “So that’s something that — you sign up for the risk and you’re OK with it, but you never think the risk is that grand in the sense that it’s immediate. It was something that opened your eyes more than anything.’’

Within two days of watching the heart of their defense carted off the field, the Steelers learned that Shazier had suffered a spine injury that would require stabilization surgery — a procedure reserved for cases such as tumors, degeneration in the spine, and traumatic conditions.

It was, by far, more than just the loss of a Pro Bowl linebacker whom the Steelers considered the quarterback of their defense. It was a mortality check that sent waves through the entire league.

It led the Baltimore Ravens to put one of the fiercest rivalries in football aside as they prepared for their matchup with the Steelers last Sunday and open one of their team meetings with a prayer for Shazier.

“We said a prayer for him and he plays for the Steelers, so you know it’s bigger than football,’’ Ravens receiver Mike Wallace said at the time. “It’s about a person.’’

It led to a flood of tweets from players around the league, no matter if they were active like Eagles running back Jay Ajayi, retired like former Ravens linebacker Ray Lewis. or injured like Eagles quarterback Carson Wentz. When Browns running back Duke Johnson Jr. caught a touchdown pass last week against the Packers, he dropped to a knee in the end zone, said a prayer and made the number “50’’ — Shazier’s jersey number — with his hands in Shazier’s honor.

“You’ve got to think, man,’’ said Steelers linebacker Arthur Moats. “Shay is one of the premier players in this league from a defensive standpoint. He’s a Pro Bowler, All-Pro type guy, and at the end of the day we’re all human. We’re all a part of the brotherhood of being an NFL player. So any time you see somebody go down with a serious injury like that, it’s going to get to you.

“It’s going to touch you league-wide because of just that brotherhood that we have. It’s one of those things, it just shows the ultimate respect that people have for Shay and the type of player he is. And at the same time, we’re all in this together. We’re all risking our bodies, risking our lives ultimately, and to see somebody go down like that, it hits home for everyone.’’

Shazier’s injury was a devastating reminder of the risks involved in a brutal game. It was also a symbol of the bond between the people who play it.

“That’s the thing about football,’’ Foster said. “We go after each other in a vicious way. We enjoy the sport of trying to conquer the man in front of you, but the respect factor of what goes on in this league from player to player is very mutual. Guys realize you’re doing this for a living, you’re doing this to change your family’s life, you’re doing this to better yourself. It’s not that it’s your last option, but it’s one of the best options out there as far as just making your family more financially stable.

“And to see somebody go down the way he did or to have the certain consequences behind playing this game like that, you have to respect it. And those guys probably have the same fear too of, ‘Man, that could’ve been me.’ You never think it’s going to be you. We as athletes play this game in a sense that everybody thinks they’re Hercules. Everybody thinks they’re Superman. And to see somebody become in a sense mortal — we all are mortal but on the field we’re gladiators, immortal — and he became a mortal guy in a sense. That everybody around him dropped to a knee, it was very significant.’’

The Steelers are riding an eight-game winning streak as they get set to face the Patriots on Sunday, but also coping with the emotional and tangible loss of one of the most important figures in their organization.

Beyond being their leading tackler, Shazier was the backbone of their defense and a trusted voice in the locker room.

“Shay is a special guy with a lot of talent,’’ said coach Mike Tomlin. “Not only physically but mentally and from a leadership standpoint communication. Just not a realistic discussion to talk about one guy replacing him.’’

Moving forward has been a balancing act between managing the emotions that come with monitoring Shazier’s status and maintaining focus on games still to play.

“You process it in a sense that you still play it because of the love of the game,’’ said Foster, who had a similar experience during his college days at Tennessee when his close friend Inky Johnson suffered an injury in 2006 that left his right arm paralyzed and ended his football career just as he was projected to be taken in the first round of the NFL Draft. “His situation is a small percentage of what happens.’’

When practices end, players and coaches make trips to the University of Pittsburgh Medical Center, where Shazier began rehab this past week.

They go there expecting to keep his spirits high and leave with theirs lifted.

“I go see him and he wants to talk about the game plan,’’ Tomlin said. “He wants to know how the guys are doing. He wants to talk specifically about what is transpiring in practice settings and so forth. That’s Ryan.’’

That calm could easily be attributed to Shazier’s upbringing. His father Vernon, well-respected around the league from his years as team chaplain and motivational speaker for the Miami Dolphins, instilled it in him growing up in Broward County, Fla.

Foster said he can see it when he visits Shazier.

“The thing is, after seeing him and visiting with him, he’s more OK than everybody around him,’’ Foster said. “I don’t know if it’s a sense that he thinks eventually he’s going to be all right or this will pass, but everybody else is more panicked than he is. That’s how injuries are in a sense. He’s the guy that has a very strong faith, his father’s a minister, and he knows how to deal with this.

“I’m a firm believer that God doesn’t put more on you than you can handle, and for him, he’s able to handle this situation. However he was picked and chosen for this, he can handle it and I feel like he knows that and he feels like he’ll be OK. Everybody around him is stoic, but he’s OK. He’s smiling, he’s laughing.’’

The Steelers have found ways to honor Shazier — from the cleats customized with a picture of Shazier’s face that receiver Antonio Brown wore last week, to “#Shalieve’’ T-shirts that went on sale with proceeds going to charity, to the FaceTime call that let Shazier be a part of the locker room celebration after their emotional 39-38 win over the Ravens last week.

Wherever the rest of the season takes them, the Steelers will carry Shazier with them.

“I feel like after you get past that initial shock and that initial concern of seeing your brother go down, the next thing is, ‘OK, we’ve got to lock back in. We’ve got to mentally get back focused,’ ’’ Moates said. “I kind of think of it no different than people who have a sick parent or a sick family member. Everybody has things that are going on in their personal lives, but when you get on that field, you kind of are able to compartmentalize it.

“It’s still important, but you’re able to put your main focus on the task at hand, and I feel like that was the same situation. You’re hurt by it, because you never want to see your brother go down. You’re sad. You’re overly concerned about him. But then, once they take him out, it’s, ‘OK, we’ve got to lock back in because we still have a task at hand. We still have a job to do.’ ’’

Julian Benbow can be reached a jbenbow@globe.com. Follow him on Twitter @julianbenbow.