SPARTANBURG -- A lot to cover today, but before we get into the practice highlights, let's go over the Luke Kuechly news.

During a 9-on-7 drill, the star linebacker was involved in a pileup and left the field with head athletic trainer Ryan Vermillion. Kuechly was shaken up, but eventually returned to the sideline as an observer for the rest of practice.

Head coach Ron Rivera said Kuechly wanted to get back in there, but the Panthers held him out.

"Just wanted to be cautious. He wanted to go back in - that's why he didn't take his helmet off," Rivera said. "We're being cautious. There's no reason to expose a guy to that."

And now, the observations.

--What do you know, another day of Curtis Samuel turning heads. He put on a show during 1-on-1s against cornerback James Bradberry, first using his quickness and burst to create immediate separation on a short pattern. Notice the stutter to get himself even more open. He's been detailing his route running to great effect. Later, he ran a crisp comeback against Bradberry and there was simply nothing Carolina's top corner could do. Just too good.

--Things were getting a little heated under the helmet today. Rookie running back Elijah Holyfield got into it with linebacker Jared Norris and defensive end Bryan Cox barked at rookie guard Dennis Daley after they got tangled up in 1-on-1s. It's that time of camp.

--Center Matt Paradis and offensive tackle Daryl Williams still aren't partaking in 1-on-1s against the D-linemen. Below is a 2-on-2 highlight, where you can see Bruce Irvin and Gerald McCoy work in tandem against Taylor Moton and Trai Turner.

--With Kuechly sidelined, Jermaine Carter stepped in at inside linebacker with the first team. Ross Cockrell again worked as the first-team safety, with Rashaan Gaulden taking a bunch of reps at nickel in addition to safety.

--Catch of the day goes to Greg Olsen for this sweet one-handed reception. Notice he was up against speedy corner Donte Jackson. Olsen can still get downfield, and obviously, he's still got those soft hands.

--Another highlight-reel play moments player from the second-team defense. Gaulden, this time lined up at safety, converged on a deep ball from quarterback Kyle Allen intended for wide receiver Torrey Smith. Cornerback Kevon Seymour got his hand on the ball and Gaulden was where he needed to be to reel it in. Gaulden later had a PBU in the end zone. A solid day for him all around.

--The first hurry-up drill was going well for Cam Newton and the offensive starters, but the defense pushed back deep in the red zone. Newton tried to connect with Samuel on a quick slant, but Bradberry read it the whole way for the interception (and some revenge against Samuel).

--Their next crack at it ended with a touchdown thanks to a huge surge up front. Left guard Greg Van Roten pancaked Norris on the edge (could be the block of the camp so far) and Daley, lined up as the first-team right guard in place of Trai Turner, cleared the path for Christian McCaffrey to plunge into the end zone. Newton was so excited about it, he leapt into Van Roten's arms to celebrate.

--Allen got the second team into the end zone to cap their hurry-up drill. After buying some time, Allen located tight end Ian Thomas and fired a strike at the goal line for the score.

--Newton had one of his better deep balls of camp late in the session, connecting with wide receiver DJ Moore on a DEEP post in between Bradberry and Seymour. Newton went at Seymour, stepping in with the starters while Donte Jackson got an extended rest, again on the next play, and Seymour dropped his chance at the interception. Still, Rivera has been pleased with what he's seen from Seymour throughout camp.

"Kevon has really stepped up," Rivera said. "He's really shown his speed and his quickness. He's done some really good things and he's caught our attention. We feel really good about him as potentially one of our top three or four corners."

--After going head-to-head all day, McCoy and Turner were working together after practice, going over some pass-rush moves and counters. These two are determined to make each other better.