EAGAN, Minn. – Vikings Head Coach Mike Zimmer wants to see some yellow flags flying … at practice, of course.

The elimination of preseason games due to the COVID-19 pandemic means that teams – and especially rookies – won't have those "warm-up" games to get used to NFL officiating.

Minnesota also has been without professional officials at Verizon Vikings Training Camp practices, although two members of the scouting department donned the zebra stripes on Wednesday and Thursday.

Zimmer spoke to Twin Cities media members Friday via video conference and said "one concern" at this point in training camp is penalties.

"We've got to clean up a lot with our hands, really on both sides of the ball. Sometimes, hands to the face with the defense," Zimmer said.

He emphasized that coaches are "on them pretty good" when would-be penalties are spotted on the field or later in the film room.

"I've got some makeshift officials out there right now, but we're going to get some guys – they've started testing protocol, so we're going to bring those guys in and really tell them, 'Hey, you've gotta throw the flags. We've gotta get used to this,' " Zimmer explained.

He pointed to the 2019 season opener in which Minnesota committed 11 penalties for 100 yards against Atlanta.

"We just need to get them cleaned up. Same thing with special teams. We're going to have a lot of penalties coming there, as well," Zimmer said.

Here are four other topics Zimmer addressed during his media session:

1. Well-wishes for Rivera

Zimmer opened his press conference by sending well-wishes to Washington Head Coach Ron Rivera, who recently was diagnosed with squamous cell sarcoma.

"I'd like to say our wishes and prayers go out to Ron Rivera. He's been a good guy, known him for quite a while," Zimmer said. "I hope he pulls through this thing and stays healthy like the rest of us."

"You wouldn't wish that on anybody, but I understand the rigors he's going through with trying to coach a football team, trying to get his health back, seeing doctors, just all the things you have to do when you have some kind of sickness or disease or whatever it is," said Zimmer, who underwent multiple eye surgeries during the 2016 season. "[Saints Head Coach] Sean Payton, I've talked to him a couple times this summer— he had [COVID-19] early. You just hope for the best for everybody in the NFL."

2. Making decisions on special teams

The Vikings are grateful to have their trio of specialists – kicker Dan Bailey, punter Britton Colquitt and long snapper Austin Cutting – returning from last season and set in stone, but plenty of decisions remain on the table for other special teams phases.

"We have to find out, really, about some of these younger guys on special teams things. We'll have to find that out fairly soon," Zimmer said.

How does one make those calls with a shortened training camp and no preseason?

"I'm contemplating a lot of things. Maybe we're going to have to — maybe not tackle live — but we're going to have to have some live, full-speed drills where we go down, avoid blocks, guys try to block people," Zimmer said. "So far, it's been segmented sections, so it's trying to get them all together and understand where they have to be. We're probably going to have to do a few of those as we move forward here."

3. Getting the game-day feel

Zimmer also wants to give players a feel of game day before the real deal.

The Vikings are set to open their season at home against the Packers on Sept. 13. But Zimmer plans to take the team downtown on Friday, Aug. 28, to practice under the transparent roof of U.S. Bank Stadium.

"We're going to do it exactly how it's going to be in a game," Zimmer said of next week's practice. "Part of it is, a lot of these guys have never been in the stadium. They've never seen the locker room. They don't know the pregame routine; they don't really know anything about it. So I'm just trying to acclimate them a little bit to that, and we'll have the scoreboard going and all the lights and all that stuff, and the crowd noise that they'll hear during the game.

"[Even] halftime practice. You know, these kids have never seen a 12-minute halftime before," he added. "So we're just going to do all those – try to get them as used to it as they possibly can so the first day it's not a shock."

Zimmer said the Vikings will practice the final 10 minutes of a fourth quarter at Twin Cities Orthopedics Performance Center during Sunday's practice. When they practice at the stadium next Friday, they'll play a half "kind of like the last preseason game," head into the locker room and return to action.

4. Getting game-ready

With almost a full week of padded practices under their belt and with three weeks until the season opener, how close to game-ready are the Vikings?

"We've still got a ways to go. There's some things that I really, really like, but we still have more time to work on some of the technique," Zimmer said. "We're still installing things. We should be done with that here fairly quick. And then we can kind of package it down and focus on what we're going to really concentrate on.

"I know offensively and defensively we're still looking at a few things – 'maybe that's good, maybe that's bad' – and then kind of condense the package a little bit," Zimmer added. "We're not getting ready for Green Bay yet, but we want to start executing a lot better than what we are right now."