EAGAN, Minn. — The sun was out, temps were rising but still accented with a cool breeze, the fields were pristine green and there were Vikings draft picks, undrafted free agents and players trying out for a coveted spot on the 90-man offseason roster.

Mike Zimmer was a happy man.

"Good to have you all back; it's been a while," Zimmer said to open his podium session with media members on Friday. "It's my favorite time of the year. It was nice to get to players out here today, get a little workout. Walk-through this morning with practice this afternoon. We should have three good days, and I'm looking forward to watching these guys work. Try to figure out how they learn, try to figure out how they interact with the rest of the team and how they accept coaching, things like that. We're excited about it, a bunch of good draft picks."

The Vikings head coach is a teacher of the game first and foremost, like his father was, and his son is.

After a long winter saddled with pre-draft evaluation meetings, assessments at college all-star games, the combine and pro days culminated with a 12-pick draft class (a Vikings record since the draft became a seven-round affair in 1994), Zimmer's opportunity to teach this year's newcomers started Thursday evening with a team meeting.

This weekend will include additional meetings, walk-throughs and practices at Twin Cities Orthopedics Performance Center.

The learning can be a two-way street, with Zimmer and his staff focusing on how individual players might learn things.

He took that approach when he first got here in 2014 and began working with players he inherited.

"For instance, Harrison Smith, I really never have to yell at him because he's a guy that understands what I am saying all the time," Zimmer explained. "You can give him a look because he knows you are mad at him. Some guys just take a little bit longer.

"When we first got here, Xavier [Rhodes] made great strides as far as starting to understand the scheme and the things that we are trying to do," Zimmer added. "Some guys just take a little bit longer. [Anthony] Barr is a brilliant guy, so it doesn't take him much. Each guy is a little bit different. I had a safety one time that never wanted to be embarrassed in front of everyone else. You had to talk to him much differently than some other safety. It took him a while to get things, but once he got it, he had it."

Zimmer said it's important for a coach to "be yourself and then you see what they respond best to."

"At the end of the day, you are trying to get them to be the best player they can possibly be," Zimmer said. "Whatever buttons you have to push, that is how you try to do it. You figure out what they respond best to. Like that safety, I used to have to correct him and I would come over, put my arm around him and I would talk real quiet to him and say, 'Here is what you need to do. Try this, try that.' Then there are other guys that need a kick in the rear end."

Here are four other topics addressed by Zimmer on Friday:

1. On his advice to undrafted free agents/tryout players

The Vikings have a strong recent history of players joining the team after participating in rookie minicamp as an undrafted free agent or tryout player.

Receivers Adam Thielen (2013) and Chad Beebe (2018) are two examples of tryout players who worked their way up the roster ranks.

What was Zimmer's advice to this year's group?

"I told them last night, 'Every year we sign somebody from here, whether it be Adam Thielen or Chad Beebe or Marcus Sherels, the list goes on and on,' " Zimmer said. "I told them … 'We're looking for guys that, number one, are good people, and, number two, they have to have athletic ability. Come out and do what they're being coached to do.' I remember last year with Beebe, you could see him right away with his athleticism and the way he never slowed down when he was running a route. I think it's a little bit different for each position."

2. Difficult assessment window

Zimmer admitted the short window is hard to make comprehensive assessments on all of the tryout players.

"We've missed guys in the past, we've had them in these workouts and they've signed other places and been good players," Zimmer said. "A lot of times, it's being in the right system, being in the right fit. It's really about, 'Can the guy get lined up? You give him different formations, things like that, and if they can't get lined up right, that's kind of a red flag. That's part of it. Or if they're slow thinking when they're seeing the plays, things like that."

3. Plan for Bradbury

The Vikings first pick of 2019, North Carolina State center Garrett Bradbury, is scheduled to speak after practice.

Zimmer was asked how much the Vikings plan to work the Rimington Trophy winner (nation's top college center) at the pivot or at a guard spot.

"We'll make a decision quickly and let him go," Zimmer said.

4. AAF influx

The Vikings were one of the most active NFL teams when it came to signing players from the defunct Alliance of American Football, a pro league that started play after Super Bowl LIII but folded.

Those players are able to participate in this weekend's camp.

Zimmer said the group's recent experience with pro football and understanding practice tempo and footwork should help those players.

"They have to learn different coverages and things like that," Zimmer said. "All of these guys have pretty much been in camp before. Some of these guys look pretty good out here. We are just running around in shorts, so it's hard to tell."