SPARTANBURG, S.C. -- Panthers coach Ron Rivera doesn't yell much, so when he does it certainly grabs everyone's attention.
Such was the case on Tuesday when the mild-mannered Rivera ripped into players at midfield after what he called a "chippy" practice that included plenty of pushing and shoving, a few late hits and one "melee" involving more than a dozen players.
With his fists waving up and down, an angry Rivera warned players about the dangers of losing their cool in practice.
"We can't have chippiness or late shots toward a teammate," Rivera said afterward. "The concern obviously is it escalates and it festers and it lingers and the next time we go out on the football field somebody is taking a shot... We can't afford to afford to have anybody that we truly need get caught up in this."
There were several confrontations during the morning practice, the biggest involving a heated altercation between the offense and defense involving more than a dozen players by the time quarterback Cam Newton and others pulled players from the scrum.
Newton said there was a noticeable feistiness in the air Tuesday, perhaps a reflection of the dreary, overcast sky at the morning practice.
"You have to look at it like a double-edged sword -- on one hand you have to like the fire in the guys but at the same time you have to be respectful of guys' careers," Newton said. "When a fight breaks out anything can happen. For something that can be just for kicks and giggles, somebody can get a sprained ankle or hurt. So that was coach Rivera doing his fatherly due diligence trying to protect his players and express to us to play smarter."
There was plenty of lead up to that brouhaha.
"It's disappointing that it lingered and it lasted as long as it did," Rivera said. "I'm not going to say it was good, but it was good to see the guys have a little attitude about things. But we do certainly most want to save those for (the preseason games) and we don't want to do it against teammates."
Rivera warned players if they can't abide by his rules they'll sit out.
What concerned Rivera the most is some receivers were hit downfield while in vulnerable positions.
"We have to be smart about those things," Rivera said. "When we get a chance to hit somebody we need to square them up and put them in a good position. We don't want to hit a guy where it's an angle and it's not a good position.
The Panthers open the preseason Friday night against the Chicago Bears.
"We are at the point where we need to play against somebody else," Rivera said.
NOTES: Panthers linebacker Thomas Davis participated in team drills for the first time this summer. He's been limited in practice while battling a hamstring issue. ... Running backs Jonathan Stewart (ankle) and linebacker Jon Beason (knee) remain out of practice for the Panthers.