EDEN PRAIRIE, Minn. — Heading into his fourth preseason as the Vikings head coach, Mike Zimmer is continuing to find ways to improve.

Zimmer, who arrived in Minnesota in 2014 with two decades of NFL experience on defense, has started to spend more time with the offense and special teams units.

 "There's so many times you get to be a head coach and you're a defensive coordinator and you come in trying to able to get the defense fixed," Zimmer said. "Then, you get fired in a year or two years. So, you don't learn how to truly be a head coach."

Even through 48 games, Zimmer is still looking for areas where the he and the Vikings can do better. Zimmer alluded to the success that Patriots Head Coach Bill Belichick has had later in his career as an example.

Belichick went 36-44 in five seasons with Cleveland (1991-95). He was hired by New England in 2000 and has five Super Bowl rings with the Patriots, who have won at least 10 regular-season games in 15 of 17 seasons under Belichick.

"It takes a while to learn how to do this job, it really does," Zimmer said. "I probably shouldn't say this, but there's this guy in New England who's doing pretty damn good now, and he might've had a rough start in his deal.

"That's kind of my mentality, [which] is to continue to grow as a head coach, continue to be involved with the defense, but be a lot more involved in the overall game-type team offense, special teams than I ever had been before."

Zimmer is even considering letting defensive coordinator George Edwards call the plays on defense in a game this preseason so he can be more involved on offense and special teams.

"I know I've probably said that before, but this is the first time I've finally felt comfortable I think because we have so many guys back defensively. But, I don't want that side of the ball to slip. So, George [Edwards] and I talk an awful lot. He does an awful lot in the spring. We'll have to see how it goes once we get to camp. But, it helps feeling good about the coaches that I have."

Here are four other topics that Zimmer covered:

Zimmer positive about his eye

Fresh off an appointment with his eye doctor on Wednesday, Zimmer is positive about the condition of his eye heading into the time off.

"(My) retina is perfect, and the pressure is great," Zimmer said. "(The doctor) said he would be absolutely shocked if anything else happened to this eye the way that it is now."

Zimmer said the only restriction he has is that he won't be able to fly for the next seven to 14 days.

"I am just about out of the woods," Zimmer said. "My daughter is getting married a week from Sunday, so I'm going to have to drive to Dallas. So I guess that would be the biggest thing. As far as football-wise, I've got things that I want to get accomplished for me, and it shouldn't affect it at all."

Zimmer said that his vision was at 20/100 on Thursday after practice but that the bubble in his eye that is hindering his vision is expected to be gone in seven to 10 days according to his doctor.

The head coach has already undergone eight procedures to repair his eye and doesn't expect to have another.

"It's nice that we're progressing and maybe (surgery) number nine doesn't show up," Zimmer said. "I read that (sign) when I was driving to Kentucky and it said 'Cats have nine lives. You don't, so buckle your seatbelt.' I am hoping I don't get to the ninth life."

Vikings legends at minicamp

The Vikings have hosted a number of notable alumni at minicamp this week.

Randy Moss and Ahmad Rashad were at practice on Wednesday as they were notified that they would be inducted into the Vikings Ring of Honor in 2017.

On Thursday, Chad Greenway, Matt Blair, Jon Randle, Randall McDaniel and Jerry Burns were all in attendance for the annual alumni barbeque after practice.

"It was great yesterday to have Ahmad Rashad and Randy Moss out here," Zimmer said.  "I was able to see them down at the Taste of the Vikings so that was nice to get two great players like that. Randy Moss killed me on so many occasions. I was glad when he retired.

"I was just watching Matt Blair talk to Emmanuel Lamur, and as I've said before it's really important to me that these players that we have understand why they have the things that they do," Zimmer said. "Some of these guys that have (already) played and gave them the opportunity and let the sport grow. I think that's a really good thing for our guys. Like I told them in the meeting this morning, hopefully sometime 10 years from now some of these rookies will be out here watching them when they come out."

Riley Reiff's mentality at minicamp

Mike Zimmer knows that new tackle Riley Reiff has a quiet persona, but when the offensive lineman speaks up to his head coach, he gets his point across.

"I was really impressed with Riley Reiff. He's a tough, guy physical guy and good with his sets," Zimmer said. "He doesn't say much but when he says something he means it."

Zimmer went on to reference a quote from Reiff that he was impressed by.

"Reiff said to me 'I've made money in this league and I just want to win a Super Bowl,' that's kind of his mentality, and I think it's good for the football team."

Update on Dalvin Cook

Zimmer has already noted how impressed he has been with rookie running back Dalvin Cook through rookie minicamp and OTAs. On Thursday he cited a play where Cook outran cornerback Xavier Rhodes when speaking of Cook's chances to be a special running back in the NFL.

"I think this guy has got a chance to be pretty good," Zimmer said. "Now he's got some things he's got to work on like all young backs. But, I've been real impressed with him this spring. He's been a great kid off the field, and he's been a great kid in the meetings."