SPARTANBURG, S.C. — There were decisions that Baker Mayfield wishes he could have had back.

That was true of a couple of throws, and his wardrobe.

The new Panthers quarterback walked onto the field Wednesday morning to cheers from the fans along the fence, while wearing gear that would have been more appropriate in November, or in Cleveland.

"I was pretty stupid for wearing long sleeves and pants," he said with a laugh.

Mayfield took all of his work with the second offense Wednesday, with incumbent Sam Darnold working with the ones. Head coach Matt Rhule said that would flip Thursday, with Mayfield getting to practice with the first set of receivers.

And while working with the second group, Mayfield had some moments in which he looked like a guy going through his first practice with a new team.

"Not excited about some of the throws, accuracy-wise," he said.

He aired one past Brandon Zylstra on a deep chance, and had another go off the hands of Terrace Marshall Jr. (though Marshall did push-ups after the play to suggest he thought he should have made the play). Mayfield also threw the first interception of camp (which seemed to hang up in the air, with cornerback Keith Taylor Jr. collecting the first pick in Spartanburg).

Rhule said he liked Mayfield taking some deep shots, and downplayed the misses since receivers are also on day one, and will eventually "run under some of those."

Mostly, Mayfield thought it was a good start, but he also has a high standard as he tries to win a job.

"There's a time to be aggressive and try to push the ball downfield without being stupid and being careless," Mayfield said. "There's aggressiveness, and then there's carelessness. It's a fine line between those and knowing when to take your shots and when to not get too greedy and play in the flow of the game. If you take care of the ball, most likely you're going to win games."

— Darnold had a reasonably clean day, though linebacker Damien Wilson had a chance at an interception earlier in practice.

He also was sharp in red zone work, finding tight ends Tommy Tremble and Ian Thomas in the end zone.

Darnold has handled a potentially awkward situation with grace, and said he enjoyed working with Mayfield as they fight for a job, saying they were "bouncing ideas off each other."

When asked about the reception Mayfield got, he grinned and said "I heard a couple" of cheers for himself, but he's aware that the new guy is going to get the most attention.

Since he'll be with the twos tomorrow, he's trying to do everything he can to hang onto the job he would have had before the trade for Mayfield earlier this month created the competition.

"I can't look at the reps; I have to make my reps count," Darnold said."

— While there's an obvious concern about cornerback Jaycee Horn, who was placed on the active-physically unable to perform list Wednesday, Rhule said it was a precautionary move.

"It's not a long-term thing," Rhule said.

Rhule said Horn was sore after yesterday's conditioning test, but wanted to practice.

— Horn spent part of his time during practice hanging out with linebacker Shaq Thompson, who is also on PUP. Thompson isn't expected to miss much time, as they're confident he'll be ready for the regular season.

Thompson continued to coach some in addition to his conditioning work, and that figures to be the case throughout camp.

— With Thompson and Horn on the sidelines, linebacker Cory Littleton and cornerback CJ Henderson worked with the first defense in 7-on-7 drills.

Littleton's an established pro, so he's quality depth for the veteran linebacker and team captain.

— The quarterbacks aren't the only ones competing for jobs, and they're looking at a lot of different combinations of linemen.

During a run drill during the non-contact practice, Brady Christensen took the first snaps at left tackle, next to left guard Michael Jordan. Moments later, Ikem Ekwonu was at left tackle, and Christensen was at left guard.

That's going to continue as they sort through a new group. Pat Elflein was the first center, but Bradley Bozeman worked in at center alongside the Ekwonu-Christensen duo. Dennis Daley was all over the line, taking reps at right guard, right tackle, and left tackle.

— Yes, it was hot. It's Spartanburg; that's how it is here.

A few players were in and out of the tent during practice, with wide receiver Shi Smith and cornerback Chris Westry missing some reps.

— First man on the field? Rookie quarterback Matt Corral. He's probably going to get time to develop but he knows what he needs to do to give himself a chance.

— While the retirement of Rashaan Melvin leaves them young in the secondary, Rhule said he appreciated the class Melvin showed, calling him before camp to talk about his decision. The veteran cornerback played 10 games last year, and was the elder in the room.

In his absence, 26-year-old Donte Jackson is again the old man at his position.