CHARLOTTE — Sam Darnold is a competitor, and believes in his own ability.

But he also hasn't rocked the boat so far, and isn't going to start now.

The day it was announced that he'd back up Baker Mayfield this season, Darnold made it clear he was going to do everything he could to keep the work environment positive — which it was throughout camp as he and Mayfield competed for the Panthers' starting job.

"Yeah. Absolutely, yeah," Darnold said simply when asked if he considered himself a starting-caliber quarterback. "I believe I have all the traits, attributes, and mindset to be a starter in this league. But again, it's my job to do everything I can, . . . my role right now is backup. And I'm going to do everything I can to prepare myself to play if something happens to Baker. But at the same time, I've got to do everything I can to help him get ready for a game. . . .

"Yeah. It's tough. I'm not going to lie. But it is what it is."

Panthers head coach Matt Rhule said the grace Darnold and Mayfield showed throughout camp — in what could have been and probably should have been an awkward situation — has been a model that he shares with other players who have questions about their own playing time.

"From the first day I talked to Sam, and we made the move (to trade for Mayfield in July), I know who he is. I don't have to worry about that with him," Rhule said. "When Baker came in, I could quickly recognize who he was. So I was never worried about that necessarily. I think what's kind of cool is they became friends along the way and really supported each other.

"And the power, like when a young player comes to me and says, 'Coach why am I not getting more reps?' . . . For me to say, let's talk about Baker and Sam. These guys are both fighting for their careers and fighting for a chance to start and play, and they're both good quarterbacks and how they're handling the competition. So the rest of the team, I think, has modeled that. I think those two guys have elevated the professionalism. I think Ben (McAdoo) used the words 'as long as we don't resort to cannibalism,' they've taken it the other way. At the end of the day, it's all about the team, it's not about one guy, and I think the rest of the team has followed suit."

— Monday's practice was unusual in many ways that went beyond the declaration of a starting quarterback and the change in tone. It was also the first full practice back home after a month on the road in training camp and joint practices with the Patriots. So Rhule said he was trying to get the team into a regular-season mode, which meant altering the practice routine a bit.

It took some getting used to, as there were some moments of apparent confusion about game situations at times, and there were times when coaches (plural) expressed some displeasure with what they saw. In one example, they had what would have been a pick-six by Jaycee Horn negated by a defensive offsides penalty, so getting the details right was clearly an emphasis.

Rhule said that instead of practicing in four- or five-play segments as they did in camp when more players were getting reps, he structured practice in racks of 10 plays, which puts a little more pressure on players to be sharp. They also didn't distribute a script, calling each offensive play live to push players physically and mentally.

"Too many miscues, too many mistakes, too many penalties," Rhule said. "We really challenged them today. We didn't give them a script; everything was called, so they had to react to the whole offense. We challenged them."

He said he could see some signs of fatigue as practice went on (and it was a long one, though not a Spartanburg-hot one) but reminded players the season was just beginning.

"It's late in camp, you get back here, maybe sometimes you're hoping the end's in sight," Rhule said. "But the end's not in sight. We have a lot more work to do."

— The Panthers had a mixed bag of players available for Monday's practice, as there was a revolving cast of players coming back to work and others added to the injury list.

Wide receiver Robbie Anderson was on the sidelines Monday after missing time last week with a quad issue, but Terrace Marshall Jr. was back in uniform after he missed the second day of joint practices last week and Friday's game with a hamstring issue. Wideout C.J. Saunders was also back on the field after he missed a few weeks with a quad strain of his own, but veteran returner Andre Roberts and special teamer Brandon Zylstra were among the group of players on the side in red jerseys.

Defensive end Marquis Haynes Sr. wasn't there for personal reasons, and rookie defensive end Amaré Barno (hamstring) wasn't practicing either. They got rookie tight end Josh Babicz back to practice, but were still without tight ends Ian Thomas and Colin Thompson.

Being banged up at a few positions also forced them to adjust the practice, cutting some scheduled segments off.

Other players missing Monday included Spencer Brown, Sam Franklin Jr., Julian Stanford, and Frank Herron. Center Bradley Bozeman remained on the sidelines after last week's ankle injury, but he wasn't in a walking boot and rode a stationary bike on the side. The initial prognosis was that Bozeman might miss two or three weeks, leaving the window open for him to be ready for the start of the regular season.

— Rhule said the plan was for a good number of starters to play "at least a quarter" and perhaps more in Friday's preseason finale against the Bills, including Mayfield.

— The Panthers still need to make three roster moves Tuesday to get to the 80-man limit, after making a few cuts Monday.