CHARLOTTE — As the Panthers began their on-field work in late July, head coach Matt Rhule came to undrafted rookie defensive back Myles Hartsfield with a proposition.

At Temple, Rhule recruited Hartsfield as a running back out of New Jersey. Hartsfield even made a few unofficial recruiting trips to Philadelphia at the time.

"He was a great tailback in high school," Rhule recalled last month.

But Hartsfield, who racked up 40 touchdowns and more than 1,500 all-purpose yards in 14 games over his junior and senior seasons at Sayreville High, eventually turned into a full-time defensive back at Ole Miss. And that's how he figured he'd make his way onto an NFL roster.

But in 2020, a player with the versatility to play both offense and defense is a real asset. So Rhule asked Hartsfield to go through some running back drills.

"I was like, 'OK, maybe he just wants to see how athletic I am,'" Hartsfield said Monday, a day after joining safety Sam Franklin Jr. and punter Joseph Charlton as the only undrafted rookies to make the Panthers' initial roster.

So Hartsfield took a few handoffs and made a few cuts. In some ways, it was like riding a bike. The more he did it, the more familiar it felt.

As it turned out, Hartsfield could still play running back.

He started taking snaps in the defensive and offensive backfield during practice. He attended running back meetings for about a week during camp.

"I was a little fanboy at first. I was about to be in the same room with Christian McCaffrey , the same guy I was playing with and traded for in Madden last year," Hartsfield said.

But most of all, playing offense just seemed right.

"I was excited because I felt like going to college, I should've played running back. And I wanted to play running back," Hartsfield said. "But going to school as an athlete, and growing up with the parents I grew up with, you don't second guess what a coach is trying to tell you."

Hartsfield had days during camp where he'd intercept a pass on defense, then run in a touchdown on offense — sometimes in the same period. During one practice at Bank of America Stadium, Hartsfield dashed across the field with two equipment managers who helped him change from an offensive to defensive jersey.

"They were trying to rush because they were like, 'Myles, they want you in on the next play!' I couldn't even breathe," Hartsfield said with a laugh. "They were tightening the pads way too tight, and I'm going crazy. I was like, I need to calm down, take a deep breath."

"I was doing anything I could do — special teams, offense, defense. Whatever my role was going to be, I was going to do it to the best of my ability to make the team."

Jokes aside, Hartsfield hadn't taken a carry since he was in high school.

"I talked to my (college) DB coach, and he was like, 'You're playing offense? I never knew,' because I didn't play much at prep school," Hartsfield said. "It was a big surprise to the people at Ole Miss. But the people I've known since I was five, they've been waiting for this moment."

Hartsfield is energetic, jovial, and a "the more you can do" kind of player. Between Sayreville and Ole Miss, he spent 2104 at East Coast Prep, a one-semester postgraduate school in Massachusetts. That team had plenty of running backs, so coaches moved him to safety.

"I'm a guy who, if coach tells me go be the kicker, I'm going to say alright, and I'm going to do it," Hartsfield said.

The only problem was, Hartsfield had never played defensive back before. So he had to turn to some creative learning methods.

"I just watched some YouTube clips," he admitted. "That's when it all started, me playing DB, just me buying into a system."

Hartsfield's raw athleticism made his transition easier. He was a high school All-American in track and field and placed fifth in the triple jump at the 2015 New Balance Nationals.

"I jumped 51 feet in high school, so it was something I really enjoyed," Hartsfield said.

Ironically, Hartsfield claims he didn't prepare much for that. But the fact that he was able to succeed is much like his ability to pick up a ball after years of playing defense and still be effective as a running back.

"If you put me in a situation, give me a little time, I'll be able to adapt and overcome," Hartsfield said.

He certainly did that during training camp, earning the respect of his teammates. Hartsfield noted one reason for his success was the offensive unit looking out for him. He'd know which direction to run based on the play call, but sometimes he'd need help with his footwork.

"Nobody turned their back on me," Hartsfield said. "It really was smooth sailing, knowing both sides."

But being the only player on both units led to some good-natured ribbing.

"There was a running joke, 'Myles is telling the offense the plays, what defense we're in,'" Hartsfield said. "Or, 'Myles is telling the defense what offensive plays are coming.' And I'm just sitting there like, wait, I'm not doing either."

As camp wore on, Hartsfield focused more on defensive back. And if he plays early this season, it will likely be on special teams. But now that he's made the 53-man roster, there's a chance Hartsfield could contribute at the highest level on both offense and defense, an exceedingly rare feat.

"He does give you some versatility in a year that you need versatility," general manager Marty Hurney said. "Every time we've given him a shot either at safety or at running back, he's just shown up and done extremely well."

There's no guarantee that Hartsfield will be active for the Panthers' Week 1 matchup against the Raiders. But when he does slip a game jersey over his shoulder pads, it'll be the fulfillment of a lifelong dream — no matter what position he plays.

"Being from (New) Jersey, we know how to adapt and overcome," Hartsfield said. "When my name is called, whether it's on offense or defense, I'll make the best of it."