And Riley's NFL footprint could get even bigger over the next few years.
Murray and Mayfield face each other Sunday at Bank of America Stadium (4:05 p.m. ET, Fox) in a battle of 1-2 teams. Hurts is among the early front-runners for 2022 NFL MVP.
And current USC quarterback Caleb Williams is on the early Heisman Trophy watch list and could be on a path to join former Heisman winners Murray (2019) and Mayfield (2018) as a top pick of the NFL draft when he becomes eligible in 2024.
What's Riley's secret to QB development? It could be how he builds an offense around his quarterbacks' strengths instead of making them adapt to a system. But there are other commonalities too. Carolina coach Matt Rhule, who faced Riley at Temple and Baylor, said all three in the NFL are "alphas and leaders.''
Rhule added that each being uniquely different in style is a credit to Riley, who was a quarterback in high school before a shoulder injury ended his dream of being a big-time college and NFL star.
"He always tailored his offense to each quarterback.'' Rhule said. "With Baker, it was way more dropback. Kyler did things [with his mobility] in the game against us I've never seen someone do.
"With Jalen, they tailored everything to him with the quarterback runs, quarterback draws. That's the mark of a great offensive coach.''
Riley's influence on Mayfield, Hurts and Murray didn't end when they left Oklahoma. He maintains a bond with his trio of NFL starting quarterbacks.
"I talk to them almost every week," Riley said. "I normally have the games on while I'm watching film, but if not, I'm checking in about every 15 minutes and seeing how they're playing or watching their drives. In some ways, I'm like the nervous parent when they're playing."
THERE MAY BE no better example of how Riley builds his system around the strength of his quarterback than how he used Mayfield.
Mayfield wasn't as dangerous with his legs as Hurts and Murray. So Riley helped him understand just how good he was as a leader and playmaker.
Mayfield admits if it wasn't for Riley, he wouldn't be where he is today after he left Texas Tech and walked on at Oklahoma in 2014.
"He's always been able to play matchup ball and put his guys in the best positions to win, do what they're best at,'' Mayfield said. "There's X's and O's, but then it comes down to players and not plays a lot of the times. That's a mentality he definitely instilled in me.''
Ahead of Sunday's matchup between Mayfield and Murray, Riley noted their strong work ethic.
"They're both cutthroat competitors. They both love football. They both love preparation," Riley said. "I think they both really enjoy everything behind the scenes -- the meetings and the time with teammates. You get the feeling with both of them that they're disappointed when they leave the building."
Mayfield passed for 12,292 yards, 119 touchdowns and 21 interceptions in three seasons under Riley, who was the Sooners' offensive coordinator in 2015 and 2016 and head coach beginning in 2017. Mayfield won the Heisman Trophy as a senior and was the No. 1 overall pick in the 2018 NFL draft by the Cleveland Browns.
Although he has struggled during his first three games with the Panthers -- ranking 32nd in QBR (18.9) and 31st in completion percentage (51.9) -- there is one thing Riley brought to the quarterback's game that he hasn't lost.
"To be extremely confident in what we're doing, to know what I really like, and when it comes down to it on a third down, when we have to have it, [know] what play I trust,'' he said. "In those situations, no matter what a defense is doing, what do I know and can I execute at a high level?''
That, Mayfield said, is why he, Murray and Hurts were ready to start immediately in the NFL. -- David Newton, Carolina Panthers reporter
HURTS SPENT HIS first three college seasons with Alabama before transferring to Oklahoma for his senior campaign, which means he has a lot of Alabama pride as well. So when asked about Oklahoma signal-callers being well-represented at the NFL level, he made sure to note that Tide QBs are well-represented too with Mac Jones on the New England Patriots and Tua Tagovailoa on the Miami Dolphins.
But there's no doubt that his time with the Sooners played a key part in Hurts' development and exposed him to offensive concepts that aren't readily available across college football.
"I think going to Oklahoma and being able to see how he [Riley] saw the game, he had a very different offensive philosophy," Hurts said. "He had a very unique ability to put players in positions to make plays. It wasn't like a traditional West Coast or spread system, it was one of his own. I've never seen anything like it and what he did."
Hurts rebounded in a big way after losing his job to Tagovailoa at Alabama. During his senior season at Oklahoma, he threw for more than 3,800 yards and 32 touchdowns with eight interceptions while rushing for 1,298 yards and 20 TDs. Those numbers eclipsed his best statistical season in Tuscaloosa, when he threw for 2,780 yards, 23 TDs and nine interceptions as a freshman in 2016 while rushing for 954 yards and 13 scores.
He finished second in the Heisman Trophy voting in 2019 behind Joe Burrow and ahead of the likes of Justin Fields, Chase Young, Jonathan Taylor, Trevor Lawrence and Tagovailoa before being selected 53rd overall by the Eagles in the 2020 NFL draft.
"I have a lot of respect for Coach Riley," Hurts said. "A lot of respect for him and my time there." -- Tim McManus, Philadelphia Eagles reporter
IT'S BEEN FOUR years since Murray last played a down for Riley, but the two still keep up with each other often.
"I talk to him all the time," Murray said.
Their conversations usually center around life, but Riley told ESPN that every conversation he has with Murray includes a chat about the quarterback winning a Super Bowl.
That may eventually be possible, in part, because of Riley's influence on Murray.
Murray knew how to play quarterback when he arrived in Norman, Oklahoma, early in 2016 after transferring from Texas A&M. It was Riley, however, who helped Murray accelerate his growth. "He took it to the next level," Murray said. "His knowledge of the game, the way he coaches it and the way he sees it, just the relationship he has with the quarterbacks, he's great at it."
When Murray joined the Sooners, he sat behind Mayfield for two seasons before assuming the starting job after Mayfield turned pro in 2018. During that time, Mayfield became one of Murray's closest friends -- a relationship that's still going strong today. Even though they don't speak too often during the season -- they last talked after Week 2 -- Murray said he's going to love seeing Mayfield on Sunday.
Murray being able to see a good friend and former college teammate who's also the starting quarterback of another NFL team is a by-product of the Sooners' system.
"It's a testament to the guys that are in the league," Murray said. "I mean, obviously Jalen, he spent one year with Coach, did his thing, obviously doing his thing now. Bake did his thing and, again, doing his thing now. But I just think that's a testament to Coach and how we did things, the pride we took in it, the way we played.
"There's a lot of great memories, for sure."
Riley thinks Mayfield and Murray helped make each other better players during their time together in college.
"They're two tremendous players, and to have them in the same room at the same time, they pushed each other to a high level during those years," Riley said. "They were really, really good for each other. Both great competitors and both great players. And when you get to coach guys like that, it makes my job pretty easy." -- Josh Weinfuss, Arizona Cardinals reporter
Paolo Uggetti contributed to this story.