D.J. Foster erupted in laughter as the black and yellow Porsche 911 pulled into Scottsdale Saguaro High School on a muggy Monday in late July.

It was two days before the start of Cardinals training camp, and the fourth-year running back was at his old stomping grounds to discuss the improbable reality of three former Sabercats joining forces on the hometown NFL team.

Foster and rookie cornerback Byron Murphy arrived ten minutes early, allowing them ample time to exchange pleasantries with the impromptu welcome committee from the school that had formed near the football field.

The niceties paused when the roar of the Porsche seized Foster's attention. He knew it was Christian Kirk in the driver's seat, and before the second-year wide receiver could even open the door, Foster was wailing in delight at the harmony between the vehicle's paint scheme and Saguaro's school colors.

"Aww, you've got a car that matches your high school," Foster teased, pulling out his phone to take a picture.

"Relax, relax, relax," Kirk said, but a grin spread across his face as he acknowledged the synergy.

"I guess I picked the right day to drive this."

There is a sibling-like bond the young Cardinals players share. Kirk and Foster played together at Saguaro in 2011 and Murphy joined Kirk in 2014.

Even though all three went their separate ways for college -- Foster to Arizona State, Kirk to Texas A&M and Murphy to Washington – they have been reunited in the NFL. On Thursday, they will take the field together for the first time when the Cardinals host the Chargers in their preseason opener.

After Kirk greeted the assembled faculty, the players gazed up at the 'Welcome Back' signs plastered on the wall outside the Saguaro locker room – giant odes to their past success and their current standing in the NFL.

"I'll have people come by, like, 'All three of y'all went to the same high school?'" Foster said. "And I'm like, 'Yeah, man.' That's very rare. I'm proud of it, and I know these guys are too."

Kirk and Murphy have commanded plenty of attention at training camp. As the Cardinals' two most recent second-round picks, they are expected to be a big part of the team's present and future. But it was Foster who blazed the path, shooting to stardom when the others were still in middle school.

"I was the little ballboy on the sideline when D.J. was a sophomore and junior," said Kirk, who is three years younger. "Every kid at the time on our youth team wanted to be like D.J. Foster."

Foster was the biggest recruit at Saguaro in years. The hype could have ballooned his ego, but those who knew him rave about the way Foster handled the spotlight.

"D.J. was a phenomenal athlete here, and the nicest student in the world," said Ashley Crose, an American Government teacher who taught Foster and Kirk. "He would always help out other students. You never heard anybody speaking bad about D.J."

While Foster's first two seasons of varsity football were impressive, his senior year was otherworldly. He racked up 3,058 rushing yards and 54 touchdowns in 13 games, including a playoff contest in which he carried the ball 20 times for 508 yards and 10 touchdowns.

"When people hear that it's, 'Aw, man, you were running up the score,'" Foster said. "No, it was like 80-60. … I remember (former Saguaro star) Mike Brown, who played at Nebraska and was a big idol of mine, was on the sideline for that game. That was a big moment for me. I got to chop it up with him."

Kirk was on the field that night -- the rare freshman on varsity -- and as he and Foster replayed the game in their minds, Murphy looked over and shook his head.

"Ten touchdowns?" Murphy said. "That's different."

A few weeks later, Foster led Saguaro to a second consecutive state championship, rushing for 221 yards and a touchdown. Minutes after the final buzzer, he passed the torch.

"He just looked at me and said, 'Be better than me,'" Kirk said. "'That's all I want. Be better than me.' That stuck with me."

If anyone was destined to be an NFL player from a young age, it was Kirk.

"With Christian, you kind felt like there was something special there," Saguaro coach Jason Mohns said. "Not only because of his talent level, but his maturity. I always tell people, he was the one and only kid that I said was a pro in high school."

Even as a teenager, Kirk stuck to a strict regimen that he refused to alter.

"There would be times other people would give him cupcakes in the hall, and he wouldn't eat it," Crose said. "He would bring me the cupcake. 'Here. I can't eat this.' It didn't fit his plan. He was the most focused kid, whether it was academically or athletically. Some of those students, they would throw themselves at him, because he was Christian Kirk. Even in high school, he was Christian Kirk. But there was no deterring Christian."

Kirk finished his high school career with 3,943 receiving yards and 52 touchdowns. He played running back as a senior and added 1,692 rushing yards and 25 touchdowns, averaging 10.6 yards per carry.

Even though he had one the most decorated prep careers in Arizona history, Kirk, ever the pragmatist, wasn't counting on the NFL quite yet.

"There were a lot of guys that were great high school football players that went to the next level and fizzled out," Kirk said. "You'd never hear their name again. For me, I was like, 'I need to go to college first and make sure that doesn't happen.'

"Seeing D.J. go and do his thing was a little reassuring, like, 'Alright, maybe I'll be all right at the next level.' But it was one step at a time. I need to go to college and I need to be an elite player at that level. Then we can think about the NFL after that. It's everybody's dream, but it's not like I was, 'I'm the Gatorade Player of the Year, I'm for sure going to the league.'"

When Kirk was a senior, Murphy transferred in from Marcos de Niza High School in Tempe. The junior cornerback/wide receiver clearly had the talent to be a big-time player, but was on his third high school in three years and in need of some guidance.

The day Murphy arrived, Mohns sat him down and explained the benefits of becoming Kirk's protégé.

"I don't think he actually had an option not to," Kirk said. "Coach Mohns legit walked Byron up to me and introduced me. He said, 'You do not go anywhere without him. You do whatever he does.'"

With Kirk's mentorship, Murphy began to blossom, accepting the structure and expectations at Saguaro.

"When I got here, the culture was so different," Murphy said. "I knew I had to come in and work. … (Kirk) was like a big brother to me. Whatever he did, I'd try to do it, too."

Kirk and Murphy were a dynamic duo in 2014, leading the Sabercats to a state championship. Murphy was phenomenal on both sides of the ball as a senior, catching 88 passes for 1,733 yards and 21 touchdowns while playing lockdown cornerback. He even dominated a second sport.

"He was a point guard and could have played Division I basketball," Mohns said. "People don't know that about him. I think he won a slam dunk contest at the University of Washington against all their football players. He was just a dynamic athlete. Very instinctual and very fluid. You just knew right off the bat he was special."

Murphy could have been one of those stars that never reached his potential, and is grateful for the support system he found at Saguaro. He fulfilled a lifelong dream by making the NFL, but still looks back wistfully at those defining years.

"This was the best time of my life," Murphy said.

Foster was the first to arrive with the Cardinals. He nearly signed as an undrafted free agent in 2016, but a recruitment phone call from New England coach Bill Belichick was too much to turn down.

Foster made the Patriots' roster as a rookie and won the Super Bowl. He was on their practice squad the next season when the Cardinals came calling.

"I tried to go away, but I just keep finding my way back to Arizona," Foster said with a smile.

Kirk followed in 2018. He was the Cardinals' second-round pick after a stellar career at Texas A&M.

"I was blown away, in shock," Kirk said. "I've still got to pinch myself sometimes that I got drafted back home, because this is the last place I thought I was going to end up."

Murphy completed the trifecta in April. Projected to go in the first round of the draft, he was still available after the first day. The Cardinals had the first pick of the second round, and rumors quickly began to swirl.

"The next morning I'm getting texts and calls from people, like, 'We're definitely getting Byron,'" said Kirk, who attended Murphy's draft party. "I didn't call him or text like, 'Hey, get ready, you're coming to the Cardinals,' because you never know what's going to happen. Until that pick is in, you never know.'

"I was sitting in the back just waiting, like, 'Come on, we've got to pick him. We've got to pick him.' He finally got the phone call, and my adrenaline – I was nervous too. I felt like I was getting drafted."

When Murphy transferred to Saguaro in 2014, he watched high school footage of Foster and had a front row seat to Kirk's greatness. Five years later, he was on the Cardinals with them, the highest drafted among the three.

"I was just following in their footsteps," Murphy said. "They led it, and I just had to follow."

Murphy was stretching at the outset of a practice earlier this offseason when Kirk and Foster stepped into his line of sight. This is crazy, Murphy thought.

Foster's eureka moment came last preseason, when Kirk whizzed past him on a punt return.

"Unbelievable," Foster said. "This is my little bro. He's out here returning punts and I'm out here blocking for him."

Kirk, Foster and Murphy play different positions, so they don't spend a bunch of time together during training camp, but the support is omnipresent.

"It's like a comfort blanket," Kirk said. "You come into the league – especially for Byron, who is experiencing it right now —and you're in a locker room full of guys you've never met before or never had an experience with. At the end of the day, I can walk 10 feet over to D.J.'s locker or 10 feet over to (Byron's) locker. You have that relationship that's just comfortable."

The three are at different stages of their NFL careers.

As a former undrafted free agent, Foster always feels like his spot in the league is tenuous. He is recovering from a torn ACL but seems to have an inside shot at making the 53-man roster due to his versatility.

Kirk is on the precipice of becoming a breakout star after catching 43 passes for 590 yards and three touchdowns in 12 games in his first season.

Murphy is a rookie who must acclimate quickly, projected to play a significant role in the secondary due to the suspension of cornerback Patrick Peterson.

No matter how their careers turn out, they will always be Saguaro royalty.

"D.J. came back last year," Crose said. "It was my fifth-period class. He came in, opened the door and gave me a big hug. The other students were just in awe. I remember one girl said, 'Mr. Crose, you just hugged D.J. Foster.'"

Mohns coached each of them in high school and is soaking up every moment of this unlikely NFL reunion. He attended Saturday's Red-White practice, chatting up Kirk and Murphy afterward.

There is one moment that encapsulates Mohns' current state of jubilance. It came inside a nail salon last October.

"I took my wife to get a pedicure," Mohns said. "I know that's not a manly thing to say, but we were sitting there getting pedicures watching the game, and Christian caught the touchdown to win it (against the 49ers). I about kicked the lady in the face that was working on my feet.

"You just can't describe it. It's like being a proud parent. I've got two young ones, and any time my daughter does something for the first time, you just get that rush and that feeling of pride and joy. I get that same thing from those guys."