Clemson coach Dabo Swinney will coach against Mack Brown for the first time Saturday. File/Gwinn Davis/Special to The Post and Courier

CLEMSON — Rare is it that Coach Dabo Swinney can go unnoticed in public. After more than a decade of his face popping up on television, Swinney is ingrained in the collective football consciousness. 

But back in Feb. 2009, no one at Texas' practice facility paid Swinney any mind.

"Heck no," he said Tuesday, shaking his head. "They didn't know who I was."

That was fine by Swinney, who was in town with his staff for educational purposes. The group was the guest of Mack Brown, then entering his 12th season as the Longhorns' coach. The visit informed Swinney as he prepared for his first season as Clemson's head man, a coaching retreat led by one of the most respected minds in the game.

The trip sprouted a friendship for Brown and Swinney, who will be on opposite sidelines for the first time as head coaches Saturday, when No. 1 Clemson visits Brown-led North Carolina. The Tar Heels are something of a reclamation project for Brown, sure, but Swinney said he doesn't expect to coast to an easy win — and he's not just being polite.

"He's got enough to win with," Swinney said. "And enough to beat us."

North Carolina's path to an upset starts with freshman quarterback Sam Howell, who turned down a Clemson offer and who Swinney compared to Cleveland Browns quarterback and 2017 Heisman Trophy winner Baker Mayfield. Howell starred in the Tar Heels' first four games and enters Saturday having completed 75 of 117 passes for 1,024 yards and nine touchdowns with two interceptions.

Clemson, of course, has an exciting, young quarterback too: Sophomore Trevor Lawrence is considered by many the most talented signal caller in the nation.

Lawrence was 9 years old when Swinney and Brown first met; Howell was 8. It was a different time. Brown was barely three seasons removed from the Longhorns' national championship win and Texas was still a perennial powerhouse. Swinney was a novice.

The two were put in touch by Woody McCorvey, a former Alabama assistant and a longtime Clemson administrator, and former Alabama head coach Gene Stallings, Brown said at ACC Media Days in July.

"The two programs are run pretty much alike," Brown said of Clemson and North Carolina. "There's not much difference. We will do the things Dabo's doing."

That's partly a product of their meeting more than a decade ago. After wrapping up the 2008 campaign, during which Swinney took over midseason as Clemson's interim coach, he tried to connect with a bunch of veteran coaches. Brown was the only to invite him over, Swinney said.

Swinney was struck by the faster-paced culture of Austin, Texas, a city of nearly 1 million people, but he was also enamored with Brown's handiwork. He was flabbergasted when he realized Texas had locked down their recruiting class for the next two seasons.

"They were recruiting sophomores. It was crazy," Swinney said. "But, you know, it's Texas. Everybody wants go there."

Now, people say the same thing about Clemson. But first Swinney needed to learn. He spent some alone time with Brown, bouncing ideas, running down a list of questions.

"He'd answer like three (questions) at one time," Swinney said. "He could almost read my mind."

Swinney and his staff returned home to Clemson, minds and notebooks filled with knowledge. Brown led Texas to the national title game that season, but by the end of 2013 he had been forced out. He pivoted to television, lending his expertise to ESPN broadcasts. Every so often, he'd text Swinney before a big contest for the Tigers: 'What are the keys to the game?'

Some expressed surprise when Brown, 68, signed on to coach North Carolina this past November. Even Stallings, one of Brown's closest friends, is skeptical.

"I don't know if that's a good decision, or a bad decision," Stallings said in a phone interview.

Brown, though, has injected life into the previously moribund Tar Heels. He first earned some key recruiting victories, including flipping Howell from Florida State. And after North Carolina's upset win over South Carolina in the season opener, a video of Brown dancing in the North Carolina locker room, surrounded by gaga players, went viral.

"I wanted to come back to have fun," he said. "The dance I did is pretty embarrassing. I didn't know there would be video on it either."

See? Things are different now. Cell phones videos are a fixture in post-win locker room celebrations. But Brown is learning — and so are his young Tar Heels. After following up the Gamecocks win with a 28-25 victory over Miami, North Carolina has stumbled in losses to Wake Forest and Appalachian State.

Swinney has been paying attention, noting that the Tar Heels are just a "couple plays away from being 4-0." The Tigers, meanwhile, are 4-0, and oddsmakers predict a comfortable Week 5 win.

Swinney joked he plans on texting Brown on Friday night. What are his keys to victory this week?

"We'll see if he responds," Swinney said. "I doubt it."

Follow Joshua Needelman on Twitter at @joshneedelman.

Joshua Needelman covers Clemson for The Post and Courier. He's a Long Island, N.Y., native and a University of Maryland graduate.