EAGAN, Minn. -- Nick Easton's season is expected to be over before the Minnesota Vikings play their first preseason game.

After seeking a second opinion for neck and back injuries this week, Easton underwent surgery Thursday morning to correct a herniated disk in his neck, the guard's agent, Joe Linta, told ESPN's Adam Schefter. Although the injury is likely to keep Easton sidelined for the 2018 season, it is not expected to be career-ending.

Coach Mike Zimmer announced Thursday that Easton would be placed on injured reserve.

Easton last practiced Friday before missing the Vikings' annual evening practice Saturday. Minnesota's starting left guard had been filling in at center in place of Pat Elflein, who remains on the physically unable to perform list while recovering from offseason ankle and shoulder surgeries.

The Vikings also are missing right guard Mike Remmers from the starting offensive line as he recovers from an ankle injury suffered during the team's fourth practice. While the Vikings have yet to publicly discuss a timeline for Elflein's return, Remmers' continued absence is deemed more precautionary than concerning.

The injuries to three starters have forced the Vikings to shuffle personnel along the offensive line. Replacing Easton at left guard is Tom Compton, who is expected to remain there when Minnesota plays in Denver on Saturday. Former practice squad member Cornelius Edison is filling in at center while last year's fifth-round pick, Danny Isidora, is at right guard.

Easton's prolonged absence brings into question how Minnesota will find its Week 1 starter at left guard.

Compton and Isidora have six NFL starts at guard between them. Another player Minnesota has been rotating in at both tackle and guard is Aviante Collins, an undrafted free agent whose 4.81-second 40-yard dash at the 2017 NFL combine was the third-fastest ever by an offensive lineman. Former Eagles practice squad guard Josh Andrews and sixth-round pick Colby Gossett also may be considered options at some point.

To bolster its waning depth, Minnesota may look to the free-agent market. The team is expected to have a list of names to consider before departing for Denver, a league source told ESPN.

"We're looking at all free-agent areas, really," Zimmer said this week. "That's what those guys do at night. They come in here and watch -- heck, they watch other teams, they watch guys on the street. So yeah."

On Thursday, Zimmer gave a vote of confidence to the players he already has in camp.

"I know everybody's nervous about our offensive line but I like the mentality of those guys," Zimmer said. "I like how they work. I'm around them quite a bit. They're going to figure out a way to get it done. Calm [down]. Tweet that. It's my new saying. We're going to get ["Tweet that"] on the Mike Zimmer Foundation T-shirts. Tweet that."

Easton's athleticism allowed Minnesota to operate an effective screen game in 2017 that relied on offensive linemen getting to the second level. He had the highest pass-blocking efficiency on the offensive line, per Pro Football Focus, and was just one of five guards to play more than 400 pass-block snaps without allowing a sack. He gave up only three quarterback hits and nine hurries.

"He's a tough guy that does a great job of finding a way to get his job done," Zimmer said. "He's very athletic. He doesn't give them the same thing twice. Cut them, stay up high, he might grab them once in a while. That's how he plays."

Before training camp, Easton spent the offseason rehabbing from surgery after he broke his ankle in Green Bay in December.