San Francisco 49ers head coach Kyle Shanahan wants his team to be tough and irritating. However, while competition and getting heated with each other are fine, he doesn't want his players end up punching each other.

That's where he draws the line, and that is exactly what he had to emphasize after stopping practice last Tuesday because of the full-on brawl between Brandon Aiyuk and Fred Warner.

Shanahan was reportedly angry with the 49ers after what transpired during camp, and on Friday, he broke his silence on what he told the team regarding the ugly incidents.

“I want everyone challenging each other. I don't care how much crap each other talks; I don't care how close they get to fighting. They can do whatever they want to get themselves to be as intense as they want and bring the best out of each other, which happens a lot that way. And it's the same on the field,” Shanahan said, per ESPN.

“But once you throw a punch, you get ejected or you get a penalty, and we pride ourselves on, I want people to be irritants, I want people to get as close as they can to all that stuff. I want people to get right on the line where they're about to black out, but you can't black out on the football field or you cost your team.”

Kyle Shanahan certainly makes a great point. American football is a physical sport, and so playing with intensity and with your body on the line is something common. However, at the end of the day, there's a difference between playing physical and with violence.

One just can't simply punch another. If it happens to the 49ers in a real game against a different opponent–and not their teammates in practice–they'll surely be in big trouble.

Fortunately that's why training camp is there. Aside from getting used to new schemes and developing chemistry, it could also very well be an opportunity for players to learn how to handle themselves against their opponents–as irritating as they may be.