EDEN PRAIRIE, Minn. — The Vikings first week of organized team activity practices has arrived.

The offense and defense will be able to compete against each other for the first time in 2017, but tackling will not be allowed.

The team announced on Monday that Head Coach Mike Zimmer will be **taking some time away** from Winter Park so that he can rest and recover from an eye surgery he had last Wednesday. It was the eighth procedure that Zimmer has had since discovering that he had a torn retina last fall.

Zimmer hosted a **free football camp for 350 young people** on Saturday and spoke to members of the media. He said he is excited that his team is reaching Phase 3 of its offseason program.

"It will be fun. Our guys have done an unbelievable job this offseason and in the weight room and Phase 2 in the classroom," Zimmer said. "I love how this team works. They pay attention to detail. I'm excited about this football team."

The Vikings offensive and defensive units were able to spend time working on schemes independently during Phase 2. Instead of the likes of Pro Bowlers Everson Griffen and Linval Joseph along the defensive line, the offense has just lined up across from trash cans spaced across the line. While liking a lot of elements so far, Zimmer knows it is early.

"I've seen them run plays against garbage cans right now, so it's the best offense against garbage cans I've seen," Zimmer quipped.

The 10 OTA practices are voluntary and lead up to a mandatory minicamp June 13-15. The Vikings are scheduled to have OTA practices Tuesday, Wednesday and Thursday this week.

Here are four things that the Vikings.com crew is most interested in watching:

1. An opening at linebacker | By Lindsey Young |**@LindseyMNSports**

While there's likely to be a number of different positions hashing themselves out, one I'm most interested in watching throughout OTAs is linebacker.

Minnesota's linebacker situation is an interesting one because there are multiple factors at play. Eric Kendricks and Anthony Barr surely have their starting spots locked in, but in the wake of Chad Greenway's retirement, the third starting linebacker remains to be named. The Vikings and other NFL teams have turned to a nickel defense more in recent years, but when the team is in its base 4-3, who will linebacker No. 3 be?

Edmond Robinson, Emmanuel Lamur and Kentrell Brothers are all returning from the 2016 roster. While none of them saw significant time on defense last season, each showed glimpses of potential through their special teams contributions.

The Vikings also drafted two linebackers in April: Ben Gedeon (120th overall) and Elijah Lee (232nd overall) out of Michigan and Kansas State. It will be interesting to see if and how these two are able to come in, mesh with the other linebackers and contribute on defense.

2. Can Alexander shine as new nickel? | By Mike Wobschall |**@wobby**

Even though the offense has seen the most change this offseason, it's actually a player on defense who has me most intrigued heading into OTAs. That player is Mackensie Alexander, the second-round pick from a year ago who didn't see much time as a rookie because veterans were holding down the fort just fine.

One of those veterans was Captain Munnerlyn, who was a solid nickel cornerback for the Vikings but who now is a solid nickel cornerback for the Caroline Panthers. That leaves a vacancy in the lineup and it provides Alexander a shot to earn some playing time. Do the Vikings view Alexander as a possible replacement? If so, can he step up to the challenge and fill this void? And if he can't, who does coach Zimmer turn to next?

A lack of impact from Alexander last year was more the product of lack of opportunity than a lack of ability, in my view. But that line of thinking is gone now. Alexander likely has the first crack at the nickel role and his campaign to win the job enters a big phase with the launch of OTAs this week.

3. Interesting additions at receiver | By Eric Smith |**@EricLSmith*** *

The Vikings currently have a dozen wide receivers on their roster, and will likely take all of them to training camp. While the top of the rotation appears set, there might be some intrigue for the final spot or two.

Stefon Diggs and Adam Thielen are back after a year in which they each topped 900 receiving yards. Both players have established themselves as key cogs in the Vikings offense.

Laquon Treadwell will be looking for more production after posting just one catch as a rookie, and the Vikings also recent brought in big-bodied veteran Michael Floyd. 

Jarius Wright is back for his sixth season in Purple and will vie for more playing time after recording 11 catches in 2016. The Vikings also have Isaac Fruechte, a player they elevated to the active roster for the season finale.

A pair of rookies — Rodney Adams (fifth-round pick) and Stacy Coley (seventh-round pick) — could compete for both playing time in the slot and a chance to be Minnesota's kick returner.

German-born Moritz Böhringer made international headlines a year ago as a sixth-round pick before spending all of 2016 on the practice squad. Cayleb Jones and Mitch Mathews were added as free agents this offseason, and RJ Shelton is an undrafted free agent from Michigan State.

The Vikings will likely keep either six or seven wide receivers on their 53-man roster. While those decisions are a long way from happening, players can get an early edge on the number crunch by performing well over the next few weeks.

4. Overhaul of the offensive line | By Craig Peters |**@pcraigers**

The Vikings challenges on the offensive line were well documented in 2016. Injuries forced Minnesota to used eight different starting lineups, and the Vikings didn't use the same combination of five players in three consecutive games.

This offseason, the Vikings added to the position group early in free agency, signing tackles Riley Reiff and Mike Remmers. Minnesota also traded up to draft center Pat Elflein in the third round and added guard Danny Isidora in the fifth.

An offensive line's goal of having five players function as one unit is best helped by reps, so OTAs provide valuable time for this to occur. Another benefit is that new offensive linemen will have reps against a strong Vikings defensive line that features talent and depth across the front, adding quality to quantity of reps.