CHARLOTTE — The first time Christian McCaffrey heard a Zach Bryan song, he thought it felt familiar.

The first time McCaffrey met Bryan, he felt the same way.

The Panthers running back and the rising country star are hosting a benefit concert Friday night at the Fillmore, with proceeds going to 22 and Troops. Bryan's a member of McCaffrey's board for the foundation, and they're partnering with REBOOT Recovery, to help active-duty military and veterans who are fighting the battle to overcome trauma and PTSD.

McCaffrey's going to play some piano during the show, but Bryan will be doing the heavy lifting when it comes to music, bringing his stripped-down style to a bigger stage than his earliest recordings.

The Oklahoma native became a viral sensation with low-tech videos. Friends would film him with an iPhone singing the songs he wrote, and he grew a grassroots audience, one that was looking for an authentic sound.

"He's very, very true to himself," McCaffrey said of Bryan.

His music isn't what you'd describe as mainstream country by any means, and it stuck with McCaffrey as soon as he heard Bryan's "Heading South" the first time. In the video, Bryan's sitting by a campfire, belting out the lyrics he wrote, eyes closed and voice cracking, a raw performance of heartfelt song — about a young performer who bucks the trends of the music business, railing at an industry that only cares about a "worthless dollar sign."

"I loved it right away," McCaffrey said. "That's the kind of music I like. Words that mean something. You can hear it in his voice how much he means what he's saying. He's got a unique voice, and it's more than just country.

"I relate to a lot of the songs in a lot of ways, so it's easy listening for me. Also, I thought it was cool, I heard that song after living in the South for a few years now and that song is true. The South is a hell of a place, especially North Carolina."

The fact McCaffrey wanted to help military veterans also gave him an easy link with Bryan, who's an active-duty member of the U.S. Navy. But the songs Bryan sings reminded the star athlete of his close relationships with his high school friends from home.

"I love how he talks about his hometown," McCaffrey said. "To me, it reminds me of my boys growing up. All my friends from home are still my best buds today."

And now that he's gotten to know Bryan a little, McCaffrey's reminded of a former teammate as well.

"Zach is a great guy. He's a hell of a person along with a great talent," he said. "Down to Earth, humble, overall great guy. You never know what someone who's 'famous' is going to be like. He's someone who makes you forget what he does and talk about who he is — a lot like Luke Kuechly in that way.

"Just a good guy to be around."

Friday night, they'll get a chance to hang out and play and sing, and do it for a cause that's meaningful to both of them.