While the rest of Charlotte was hitting the lakes, the links or avoiding DNC road blocks over Labor Day weekend, two of the Panthers’ Pro Bowl players were going back to work.

Wideout Steve Smith and middle linebacker Jon Beason – team captains and cornerstones of the offense and defense, respectively – returned to practice Sunday following lengthy layoffs.

Smith missed two weeks recovering from a foot infection, while Beason was out for nearly a month after pulling his hamstring during training camp. Both expect to start in Week 1 at Tampa Bay.

Running back Jonathan Stewart remains out with a sprained ankle, an injury he sustained against the New York Jets on Aug. 26. Stewart ran on the underwater treadmill Sunday, and will be re-evaluated later in the week, coach Ron Rivera said.

Smith said he’s not certain how he developed the infection, which caused swelling in his left foot and sidelined him for the team’s final two exhibition games. Smith, who has been resting at home and taking medicine for the infection, said he wasn’t able to wear a shoe on his foot until Friday.

“We honestly don’t know” what caused it, Smith said. “It was just one of those things where everyone looked at each other and said, ‘Whoa, this isn’t supposed to be happening.’ So just trying to get through that part.”

Rivera said Smith hit the ground running Sunday when he lined up with the first-team offense.

“It was good to have Steve back. Right off the bat he went back to his normal practice mode – 100 percent, all the time,” Rivera said. “So it was a lot of fun watching Steve back on the football field for sure.”

But Smith said he’s not yet where he needs to be physically.

“I’ve been out for 12 days, so I’ve got to catch back up with these guys and get in tune and get back on their page,” Smith said. “(Brandon) LaFell and (Louis) Murphy have run a lot of routes with Cam (Newton) and throwing after practice. I haven’t had the opportunity to get there. So I’m behind. I have to play catch-up.”

So does Beason after missing all four exhibition games for the second year in a row. Beason sat out the preseason last year dealing with Achilles tendinitis only to rupture the Achilles in the regular-season opener at Arizona.

Beason underwent season-ending surgery the following week on his left Achilles. He participated in the first 12 days of training camp before tweaking his hamstring in the same leg.

Beason split reps Sunday with Jason Phillips, who filled in for him during the exhibition schedule.

“I feel great. I haven’t tested the hamstring at top-end speed, but I don’t feel it at all,” Beason said. “If I could put a number on it, I guess I’d say about 85 percent. But as we get closer here, there will be times at practice where I really get to open up and see how it feels.”

Rivera said he is not worried about Beason getting injured in Week 1, as he did a year ago.

“I think this offseason’s been a little different. He went through OTAs and minicamp in a limited capacity. Then he came back and did a little more,” Rivera said. “I was excited in what we saw the first couple weeks until he tweaked that hamstring. He’s been on the road back. I’m not very apprehensive.”

Beason is a three-time Pro Bowler who owns four of the top five single-season tackles totals in team history. Smith, the franchise leader in every major receiving category, has been to five Pro Bowls, including last season when he caught 79 passes for 1,394 yards and seven touchdowns.

On the first day of camp, Smith said he hoped the Panthers could double their offensive output from last season when they finished in the top seven in the league in scoring (25.4 points a game) and total offense (390 yards a game).

Averaging 50 points and 780 yards might be unrealistic. But Smith’s point was the Panthers should be better in their second season in Rob Chudzinski’s offense.

“Offensively, hopefully we’re heading up,” Smith said. “But you can’t rest on your laurels from last year or believe you have it. You’ve got to work just as hard to stay on top or stay in the middle and work your way up to the top.”