EAGAN, Minn. – The Vikings returned an already dominant defensive line, and they also have several young lineman who can add depth as they develop.

Vikings Head Coach Mike Zimmer spoke to media members after Thursday morning's walk-through session, which was held in TCO Stadium at Twin Cities Orthopedics Performance Center, and fielded questions about three second-year defensive lineman.

Zimmer said that Jaleel Johnson, who was drafted 109th overall last year, has improved significantly. He pointed out that Johnson is a former wrestler who "wanted to get in wrestling matches" with offensive lineman, "instead of locking them out and playing the gap he's supposed to be in."

"When a guy would come to block him, he would knock him back and jump inside, and then his gap would be open," Zimmer further explained. "He's been a lot more disciplined that way."

Johnson has been with Ifeadi Odenigbo on the interior of the line for some reps.

Odenigbo, acquired by Minnesota in the seventh round (220th overall) in 2017, is listed as a defensive end but – according to Zimmer – may be a better fit for the defensive tackle spot.

"I feel like that's the best position for him," Zimmer said. "His quickness shows up, he's a tough, heavy-handed kid. And he probably didn't have the juice that you need at that spot. So I think inside is a better spot for him."

Finally, Zimmer was asked about Tashawn Bower, who made the team last summer as an undrafted rookie and has continued to improve since then.

The defensive end bulked up this offseason, but size isn't the only positive quality evident to his head coach.

"He's a really hard worker. He's got great size and length, great speed. And he's becoming better and better with the techniques," Zimmer said.

"He's more of a power-rushing end than a speed-rushing end," Zimmer added. "But there's a lot of guys like that. His skill set is different than Danielle Hunter."

Here are four other topics Zimmer talked about during his podium session:

1. Adding Richardson to the mix

In addition to all of the returning defensive linemen, the Vikings also signed Pro Bowl defensive tackle Sheldon Richardson in free agency.

Zimmer highlighted Richardson's quickness and said that he's played the run extremely well thus far.

"We're working on some things pass rush-wise because, he's always been a guy that's been disruptive, he can get around the quarterback, but he doesn't finish," Zimmer said. "So we've been working on a lot of things with him, and I saw it happen about two or three times the other day at practice, where he got to the spot and is working on things we're teaching him when he's got an opportunity to finish at the quarterback.

"So that part has been great," Zimmer added. "He's got excellent quickness, strong, he's good in the locker room, good on the field."

2. Smith can do it all and then some

How can someone who's got it all down get better?

Harrison Smith is entering his seventh year in Purple, and Zimmer said that the All-Pro safety has "probably always been able to do pretty much anything." His familiarity with the defensive system now, though, enables him to make changes or react to something even quicker than before.

"Now I can come up and talk to him and say, 'Hey, try this today.' Sometimes, I've had safeties in the past where you talk to them about something and it might take them three days of working on it to do it. But as soon as you tell him, he'll get it," Zimmer said. "He's a really, really smart guy, and he sees things really well. He very rarely makes the same mistake twice."

Added Zimmer: "The thing I like about him, he works on his deficiencies. If he doesn't feel like he's doing [something] good, he's going to get out there and work on it."

3. From college to the NFL at nickelback

Cornerback is arguably one of the most difficult positions in the NFL.

But what makes the slot corner position especially challenging when transitioning from the college level to the pros?

"It's not near as complicated [in college], number one," Zimmer said. "Number two, all the different concepts that they have to go against – man within zone, zone – if it's just man-to-man it's not that much different, but some of the zones you might have to carry it vertical and then see another guy coming into his zone and go off the vertical. He might have to carry No. 2 on the vertical or pass a guy off. There's a lot to it."

Zimmer also pointed out that there's a "lot more room" for the nickelback.

"Guys on the outside, he's really only covering, maybe, a half a field," Zimmer explained. "That guy in the slot, he's got to cover everywhere."

4. Assessing Minnesota offensive line

The Vikings offensive line group is continuing to carry on Tony Sparano's legacy in the wake of tragedy.

Zimmer said the unit is working hard and that he and the coaches are getting looks at players in different spots. Minnesota is no stranger to adversity on the offensive line, and Zimmer wants to ensure versatility within the position group.

"We will continue to do that because there's a possibility that one guy may have to play guard, may have to play tackle, may have to play center, something like that," Zimmer said. "We're trying to figure out how we can get the best five in there and how they work best together.

"It's always going to be a work in progress, but these guys work their butts off," Zimmer added. "They come out here and they grind and work and study up in the room. They're good guys."