CHARLOTTE – Jonathan Stewart thrived as Carolina's workhorse running back in 2015, and the Pro Bowler is unquestionably the lead back entering 2016.

But two second-year running backs are working to close the gap.

Cameron Artis-Payne and Brandon Wegher became fast friends as rookie runners and they took similar approaches into their first NFL offseason.

"I'm just trying to come back better," said Artis-Payne, a former fifth-round pick from Auburn. "I've lost some weight. I've dropped around 10 (pounds). I'm getting in better shape and trying to contribute more this year. I've cut some weight already, might cut a couple of more pounds, just working on myself.

"I wanted to get in better shape and find a way to contribute to the team. That's just one of the things I thought I needed to work on. I can already tell a difference."

Said Wegher, a former undrafted signing from Morningside College: "For me, I just really worked on my conditioning and speed. I feel like I accomplished that. I tried to put together a good offseason – training and spending time in the film room. Coming out here I'm hitting the ground running, knowing the plays and making plays."

After an explosive preseason, Wegher was a spectator throughout the 2015 season. He was inactive for all but one game and went a full season without touching the ball.

Artis-Payne, however, was given a chance to show what he could do. He played in seven games, rushing 45 times for 183 yards and rushed three times for seven yards in the Divisional Playoff against Seattle. He recorded his first career touchdown in the regular season finale against Tampa Bay – an 11-yard scamper in the second quarter.

"I felt like the game slowed down a little bit," Artis-Payne said. "That was big for me moving forward. It gave me a lot of confidence in what I can do in this league."

Confidence is critical, and both runners have more of it. You can see it in the decisiveness of their cuts and the expressions on their faces in between reps during OTAs.

"Oh, absolutely. Night and day," Wegher said. "Last year at this time I was just an undrafted free agent from a small school trying to make the team and proving I deserved to be here. This year I'm still proving myself, but I'm out here with a whole different confidence. I'm just trying to keep moving up the ladder."

Artis-Payne and Wegher are playmakers striving for more opportunities. They want to prove they're capable of complementing Stewart.

Their individual improvement will only make the backfield unit stronger.

"We're very excited," Artis-Payne said. "(Stewart) is one of the best running backs in the league and we're going to see that from him again.

"We had a good year last year, and everybody thinks we can have a better year this year. That's what we're aiming for as a group."

Senior writer Bryan Strickland contributed to this report.