CHARLOTTE, N.C. – Former fullback J.R. Niklos was surprised the first time he met Hall of Fame running back Marshall Faulk with the St. Louis Rams in 2002.

“He’s got his shirt off, and you would think being Marshall Faulk, he would just be shredded,” said Niklos, who played for the Rams in Faulk’s final four seasons (2002-05). “He wasn’t. He was just like an average guy.”

So Niklos understands what Carolina Panthers running back Christian McCaffrey -- who, in 2019, joined Faulk as one of three players in NFL history to have 1,000 yards rushing and receiving in the same season -- meant last week when he said Faulk gave him “great advice” on how to stay healthy later in his career.

“Marshall used to talk all the time about how you’re risking being deficient in your nutrients [when you bulk up], and how when you’re deficient in your nutrients, that’s when you’re susceptible to injury,” said Niklos, now the owner of Acceleration Sports Performance in the Chicago area. “So he purposely put on a couple of layers of fat on his body, not only so he wasn’t deficient in his nutrients but also so he would have some padding when he got hit.”

McCaffrey, who is entering his sixth NFL season, didn’t give details on Faulk’s advice. But after missing 23 of 33 games with injuries the past two seasons, he sounded open to taking it.

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— Carolina Panthers (@Panthers) April 30, 2019

“The challenge is kind of going away from some of the stuff you’ve done, and trusting that,” McCaffrey said last week.

McCaffrey didn't miss any games his first three seasons, including 2019, when his new bulked-up physique flooded social media. That season, he had a career-high 403 touches, finishing with 1,387 yards rushing and 1,005 yards receiving to join Faulk (1999) and former San Francisco 49ers back Roger Craig (1985) in the 1,000-1,000 club.

McCaffrey was so impressive in 2019 that Faulk described the former Stanford star as a “better version of me.”

However, McCaffrey hasn’t been a better version of Faulk when it comes to staying on the field.

Faulk missed three of 96 regular-season games his first six seasons. He missed more than five games once -- his final season in 2006, when he was sidelined because of a knee injury.

His 176 games from 1994 to 2005 was tied with Jerome Bettis for the most by a running back in a 12-year span, according to ESPN Stats & Information research. And Faulk led the NFL in touchdowns (136) and yards from scrimmage (19,154) during that stretch.

McCaffrey went from being one of 34 skill position players to take part in every game from 2017 to 2019 to missing the third most games among that group the past two seasons, according to ESPN Stats & Info data. Soft tissue injuries to his right ankle, right shoulder, right quadriceps, right hamstring and left ankle caused his absence.

That’s why McCaffrey reached out to Faulk and is open to a different way of training. It’s also why coach Matt Rhule indicated McCaffrey won’t play during the preseason, saying the team is exploring ways to change the approach to practicing for a “chess piece that not many teams have.”

Faulk’s late-career success definitely caught McCaffrey’s eye.

“Years 6, 7 and 8 were really good years for him,” McCaffrey said of Faulk, who averaged 2,221 yards from scrimmage those seasons.

Niklos, once called the fastest fullback in the NFL by Rams coach Mike Martz, understands. He adapted many of Faulk’s practice habits into his own training.

“Prior to him, I trained a lot like Christian did,” Niklos said.

Niklos noted that Faulk focused on hip strength and flexibility.

“Everybody wants big quads, big hamstrings, big chest, big biceps,” he said. “Those are more the 'show' muscles. Marshall solely trained the 'go' muscles -- the hip, the glutes, the [hamstrings] ... more like midbody stuff.”

Faulk also was great at avoiding big hits.

“He had so much body control, core strength, lower-body power and contact balance that he slipped off tacklers,” said ESPN NFL analyst Matt Bowen, a former NFL safety who played with Faulk in 2000 and 2001. “And he knew when to go down, to give up a couple of yards and move on to the next play.

“When I was a rookie, I learned so much from him in terms of game prep, how to preserve your body.”

Niklos added that the way Faulk was used in games, seldom on the field for more than three plays in a row, also helped.

“They were very calculated,” Niklos said of the Rams. “But if you look at his numbers, you never see that.”

The Panthers appear to be preparing for a similar strategy, with second-year back Chuba Hubbard and free-agent signee D’Onta Foreman set to carry more of the load.

As Rhule noted, McCaffrey has “had enough hits on his body.”

Now it’s up to McCaffrey to see whether Faulk’s advice works.

“If there’s some things you can [do to] tack on a few more years and prevent some stuff,” McCaffrey said, “then I’m all-in.”