MANKATO, Minn. -- From a personality standpoint, the Minnesota Vikings are a boring team. Their quarterback is polite but clearly prefers to blend into the background. Their best players are all low-key. Their coach tries hard to portray himself as a grump who wants to be left alone.

It all works most of the time, but even the coach knows that emotion and spontaneity are part of the game. So it has been interesting this week to watch Mike Zimmer implore players like Sam Bradford to be more expressive, while trying more generally to elevate the intensity level at training camp practices -- and then stepping in when some players took it too far.

On the plus side, Zimmer was thrilled Wednesday when Bradford celebrated so jubilantly after a touchdown pass that he accidentally threw the 61-year-old coach to the ground.

"Sam is a pretty flat-line guy," Zimmer said. "... I've been talking to him about taking charge and trying to do those things."

But as the week has gone on, Zimmer has grown increasingly agitated at post-play shoving matches -- most notably between receiver Laquon Treadwell and defensive back Antone Exum -- that are largely inevitable in these situations. Zimmer's anger culminated Thursday afternoon when he apparently threw two reserve players out of practice.

Zimmer said he spoke to the team about the issue Thursday. Of the Treadwell-Exum fight, Zimmer said: "It wasn't too smart."

He added: "They've been hitting each other for a while, so some guy takes an extra shot and somebody gets upset and throws a punch or something like that. I talked to them about it [Thursday]. So, I'll see if it gets corrected."

It did not. On what amounted to the Vikings' fifth consecutive practice day in full pads, defensive end Tashawn Bower gave offensive lineman Reid Fragel an extra shove after the whistle in team drills. Fragel then pushed Bower in the back as he walked away. Zimmer erupted, reminding players that it wasn't necessary to get another push in after every play.

Later, Fragel and linebacker Noor Davis started shoving each other. Once pulled apart, both left practice, presumably at Zimmer's direction. (Zimmer spoke to reporters earlier in the day but was not scheduled to do so again until Friday afternoon.)

There is a fine line between displaying more emotion and disrupting practice and progress. Treadwell, for one, has missed both full-pads practices since his tussle. He told reporters he was dealing with an unrelated calf injury.

This is not an atypical balance for head coaches to face. We're just seeing it play out in real time during the dog days of camp.