CHARLOTTE – Laviska Shenault Jr. couldn't help but laugh when he looked at his phone.

Last Sunday morning, just before he was to suit up for his Panthers debut, Carolina's newest wide receiver saw a video of his high school highlights pop up in an iMessage from Panthers offensive assistant Garret McGuire.

"Hey, this is all we need to see today," McGuire wrote.

McGuire shot a blast from the past because he'd spent the prior weeks hearing jabs from head coach Matt Rhule about a deep-rooted Texas high school football rivalry. That pitted Shenault and McGuire's teams against each other from 2013-16, and McGuire called it "the biggest rivalry in Dallas-Fort Worth, for sure."

Shenault attended DeSoto High School the same four years McGuire was at Cedar Hill High School, both just south of Dallas. The football powerhouses are separated by just six miles and have been facing off annually since 1956.

McGuire remembered how DeSoto claimed two wins over Cedar Hill his senior year. What stung the most was when Shenault and the Eagles ended McGuire's high school playoff hopes in front of thousands at AT&T Stadium en route to a perfect 16-0 record and DeSoto's first Texas Class 6A Division II state title.

And it's fitting that Shenault's 67-yard touchdown catch-and-run last week against the Saints was so similar to plays he made when McGuire saw him in an opposing jersey throughout high school.

"I was looking at the YouTube video, and I just cut up the parts of him killing us versus Cedar Hill," McGuire said with a grin. "Shoot, there's the same play of him catching it on the sideline, breaking four or five tackles."

Today's 23-year-old Shenault is five years removed from his Texas high school football heroics. But standing in the Panthers' locker room a day after his pivotal role in the first win of the season, Shenault said the DeSoto High School state of mind is what he's drawn upon since joining the Panthers in late August.

That message from McGuire helped push him to that mindset on game day.

"It just made me lock in, in a type of way," Shenault said. "I just wanted them to know, 'You're going to get that every play. You're going to get that high school mentality.'"

His mindset manifested in 144 all-purpose yards against the Saints, including a team-leading 90 yards receiving, most of it on the touchdown, when he showed his ability to evade tacklers and then outrun them.

It was a lot like he did in those high school highlights. And those who saw Shenault back at DeSoto, such as his former head coach Todd Peterman, had a sense of déjà vu.

"My brother called me, and he said, 'Hey, Viska just scored on the same thing he did in the state championship game,'" Peterman said. "You'd just flick it out there to him, and he could go. He's just always fast enough."

Shenault's first trip to the end zone as a Panther was his first since his rookie year with the Jaguars, and Carolina's lone offensive touchdown against New Orleans. It was, perhaps, a moment as big for him personally as it was for Carolina in the game.

Peterman didn't find Shenault's performance surprising, since he delivered under pressure in high school.

"Laviska was just always well-demeanored on the field," Peterman said. "He'd get excited, but the moment was never too big or too small. I mean, you could look at his body language. You didn't know if we were up 50, down 50, or going in for the game-winning drive. He just played the same. That was always really good. He did what we asked him to do."

Peterman said his coaches at DeSoto asked a lot of Shenault. A talented basketball player as well, Shenault possessed the skill set and frame that positioned him anywhere on the football field, from the slot, at tight end, running back, or H-back. Shenault was coachable, had a high football IQ, and was fiercely loyal, a trait Peterman still commends.

"He didn't care if he got one or two or catches, never said a word," Peterman said. "We needed him maybe to do more blocking that night, never said a word. He's just one of those special people that has that.

"As I've been around a few NFL guys I've coached, they all kind of have that in common. They're willing to do the extra stuff, and you know what? They're just going to do it and not be a problem."

The can-do attitude helped Shenault carve out a spot in the Panthers' receiver rotation.

Shenault dove into his new playbook late, having been acquired in an Aug. 29 trade from Jacksonville two years after the Jaguars took him in the second round.

He posted two seasons with over 600 yards in Jacksonville and found the end zone five times as a rookie but struggled with hamstring and shoulder injuries, having his role reduced before the trade.

So when he made it to the Panthers, Shenault spent the first two weeks of this regular season inactive on game days, all while he learned a new offense and took a step back mentally. He said he looked back at his thought process and discovered ways he could help himself perform in this new opportunity with the Panthers.

"I would criticize myself," he said. "But I know what I do wrong; I know what I do right. I know what I need to do to be better. I've just got to look comfortable, and I noticed that myself."

And getting to that point required channeling some of his mindset from high school – what Shenault called the "hard-working" Texas football mentality.

McGuire has already seen what Shenault can bring, and when he made his way up to Bank of America Stadium, his former high school rival sent a message of faith to him.

"I texted him on his way in, and I was like, 'About to bring a little South Dallas to Charlotte,'" McGuire said. "He is the man. He's really, really smart. He's picked up the offense well. Obviously, you guys saw the plays he makes. He's a playmaker."

Even after a breakout debut at Carolina, Shenault knows what mindset he wants to bring to the Panthers.

"My biggest thing right now is just getting back to that high school mentality," Shenault said. "Doing whatever whenever, not thinking about it and not questioning it. Just doing what I've got to do."

And if last week is any indication, Shenault could be on track to add more to his NFL highlight reel, which now looks familiar to the old ones.