When the rigors of NFL training camp cause his muscles to tremble with fatigue and his mind to wander toward surrender, former Simon Gratz High School football standout Nydair Rouse need only remove his Green Bay Packers helmet, rub his hand over his head, and feel the indentation left by a bullet in 2016 that could have ended his life. The same way one ended the life of a friend whose death shocked the Philadelphia region 15 years ago.

“That kind of pushed me not to take my life for granted,” Rouse, 24, said in a recent interview in Coatesville, days before he left for Packers training camp in Wisconsin. “So every time I’m training, I think about that. Like, ‘Yo, that could have been my last breath.’ So if I didn’t push myself, then I wouldn’t be here.”

Rouse, a 2014 Gratz graduate, signed with the Packers on May 3 as an undrafted cornerback.

As a redshirt senior at West Chester University last season, Rouse helped the Golden Rams to their first outright Pennsylvania State Athletic Conference title since 1971. It was also the first time since 1967 that the program went undefeated in the regular season.

Loss, however, shaped Rouse as a young boy.

In 2004, when Rouse was 9, his 10-year-old friend, Faheem Thomas-Childs, was shot in the head while on his way to T.M. Peirce Elementary School in North Philly during an early-morning incident in which police said more than 90 bullets were exchanged between rival drug dealers.

Thomas-Childs died days later. Two men were eventually convicted of his murder. Weeks after the shooting, more than 8,000 people marched in honor of Thomas-Childs.

Rouse struggled to march forward in life. Like a shadow on concrete, the memory of his friend and the sudden, tragic way he died, followed with each step.

Rouse’s mother, Shamika Rouse, said the two boys were inseparable.

They had lived in the same neighborhood, she said, and attended the same schools since kindergarten, until Thomas-Childs moved and enrolled at Peirce.

“That was a very difficult time because they were so young,” Shamika Rouse, 40, said of Thomas-Childs’ death. “I didn’t even know what to do. It was so hard. There were so many small children at the funeral.”

She struggled to answer her only son’s questions: “Is this going to happen to me? Why does this happen? Why are people so mean? Why did he have to move? Why couldn’t we have stayed together?”

He was "just thinking of all the ways it could not have happened,” Shamika Rouse said. “It was hard to explain to a 9-year-old.”

Football eventually became an outlet.

In high school, Rouse became a standout wide receiver and defensive back at Gratz after transferring from Neumann-Goretti as a sophomore.

In college, Rouse had a breakout redshirt-sophomore season in 2016, earning first-team honors on the all-Pennsylvania State Athletic Conference Eastern Division defense and the all-Eastern College Athletic Conference defense. He also received Don Hansen Football Gazette all-Super Region One honors.

Still, Thomas-Childs stayed on his mind.

“All the time,” Rouse said in July, wearing a Packers T-shirt inside a Coatesville pizza parlor. “I would think ... it wasn’t supposed to happen to him because he was so young. But in the back of my mind, I was always like, ‘That could happen to me at any time.’ Not saying that I spoke it [into existence] on myself, but I would talk about it up at college, talking to my friends like, ‘Man, I could get shot any day.’

"[College] was just so different from where I grew up. I was explaining to them how it is where I come from, and then it ended up happening.”

In May, 2016, months after his breakout season at West Chester, Rouse’s black Chevy Impala — an early birthday gift — was shot about 17 times near 13th and Butler Streets, Rouse said, as he drove his younger cousins home from a children’s party.

A woman in the car in front of his, Rouse said, survived multiple gunshot wounds.

His 20-year-old friend, who was riding in the passenger seat of his car, was grazed by a bullet.

None of the children in his backseat, ages 4 through 13 at the time, were wounded.

Rouse was shot once in the head. The bullet, he said, was still lodged in the top of his head as he drove himself to Temple University Hospital after the incident.

Once there, he said, a doctor told him only a “blessing from God” could have slowed the bullet enough to not do major damage.

He was discharged later with stitches and staples. Police investigated. No arrests have been made.

Smell of fresh pizza filling her car, Shamika Rouse never knew her son was in danger that night when she drove by and saw flashing police lights.

“I was riding right past the scene of it and just didn’t know,” she said.

Her plan was to have pizza, one of her son’s favorite foods, waiting for him after he dropped off the children.

“That was one of the worst days of my life,” she said. “That was so hard to get that phone call because I couldn’t even think. I don’t even remember how I got to the hospital.”

Rouse remembers a group of guys jumping out of a car just before the shooting erupted. He still isn’t sure why it happened.

He questioned whether his new car, which had tinted windows that he thought would make him safer, made him stand out, made him a target.

His mother does, too. The car was meant to be a reward for his hard work.

Instead, she wonders, “whether it was the worst thing I could have done.”

“You know how it is in the neighborhood,” Rouse said. “People are envious if you’re doing something positive. People come from the same predicament and maybe it’s like, ‘Why him?’ That’s what I [think happened]. It was just random. It was my first time home. And I had just got my new car, so nobody knew who was inside. It’s unsolved, like normal.”

These days, Rouse seeks a new normal.

The hat he wore that night, he said, had a hole where the bullet pierced through. He also had a photo of the bullet-riddled car saved on his cell phone.

But Rouse eventually got rid of what didn’t help him move forward.

He didn’t work out much that summer. Headaches and neck pain from the shooting didn’t help, he said. But he did play the entire football season as a junior.

After his championship-winning senior season, Rouse focused on the future.

In the weeks before training camp, he visited Philadelphia infrequently. When he wasn’t working out, he spent time with his girlfriend in Coatesville.

“It definitely changed my outlook on the city when I reflect about things,” he said. “You’ve seen [shootings happen] multiple times. You grow up around it. But when it actually does happen to you, it makes you move a little differently.

"I still love Philly to death because it made me who I am, but that’s why I try to stay away as much as I can, because it doesn’t matter who you are. ... If someone’s out to [hurt somebody] it’s just bound to happen.”

What’s known for sure is that the Packers play the Baltimore Ravens in Week 2 of the preseason. That date, Aug. 15, is the 58th birthday of Rouse’s grandmother, Jacklyn Rouse, the woman his mother credits with instilling the discipline that set her son on his path.

“I’m extremely proud,” Shamika Rouse said. “It’s just so surreal. He’s worked hard, and he’s been so dedicated ever since he was a small child.”

“We’re just so grateful for him to be in this position,” she added, “coming from our background, where we didn’t really have much. But he stayed persistent and stayed dedicated and to his education as well.”

She said he has come a long way from the young boy who once gave her a birthday card containing a single dollar and words promising that, “One day there will be a lot more of these.”

“Yes,” she said proudly, “I still have my dollar.”

Dollars and zip codes may change his future, but it seems the shadow of the 10-year-old friend he lost will remain by Rouse’s side.

He doesn’t have children of his own yet, but when asked how he would describe what life was like in Philly if he does, Rouse answered quickly.

“More than anything,” he said, “I would just tell them to cherish your friends. Growing up, I lost my first friend when I was 9 years old. So the friends you make in the long run, keep them close because they might be the only memories you have from your past.”