Vikings head coach Mike Zimmer underwent emergency eye surgery late Wednesday night to repair a detached retina and will not coach tonight’s game against the Dallas Cowboys at U.S. Bank Stadium.

Special teams coordinator Mike Priefer will coach the team in his absence.

“The most important thing is the concern for Coach Zimmer and his health,” General Manager Rick Spielman said on a conference call, later adding that “it’s not worth the risk” for Zimmer to rush back.

Zimmer’s latest surgery was the third on his right eye in the past month. According to a team source, the third-year coach had been scheduled to undergo the third surgery Friday but was unable to wait any longer.

Spielman said Zimmer’s vision became worse Wednesday afternoon after the team’s final walk-through of the week. And after he was looked at by the doctors it was determined that Zimmer needed a more significant third procedure to ensure that the coach’s condition didn’t worsen.

The coach had a follow-up appointment Thursday morning, after which the decision was made that he would not coach against the Cowboys.

“As much as he wants to be out there coaching tonight, it’s in his best interest to make sure that we get this taken care of,” Spielman said.

Spielman pointed out that this is the first time Zimmer has ever missed a game as an NFL coach, not even when his wife, Vikki, unexpectedly died in 2009, when Zimmer was a coordinator for the Cincinnati Bengals.

Zimmer will be resting at home during Thursday’s game because “I know if he was at the game tonight there is no way you would be able to contain him in a box or him not being Mike Zimmer,” Spielman said.

After Zimmer led the team through the week of practices and meetings, Vikings players and coaches “are ready and prepared,” Spielman said.

Zimmer, 60, first underwent a procedure to fix a torn retina in his right eye Nov. 1, a day after scratching it during a loss to the Chicago Bears. Edina-based ophthalmologists Dr. David Williams and Dr. Scott Sanderson performed that procedure, Zimmer said, and he was back at Winter Park later that afternoon and stayed overnight watching tape with one eye.

“They said if you don’t take care of those things that you have a possibility of going blind,” Zimmer, wearing dark sunglasses, said the next day.

A week later, he revealed he had “another thing done” and was “OK.”

Spielman said that there had been optimism that each of the first two surgeries would take care of the eye injury but that was not the case. After the third surgery, Zimmer realized how serious the injury is.

“As hardheaded and as tough-minded as he is, we had some pretty significant talks one-on-one, heart-to-heart about what is important in life and what isn’t. … Potentially going blind in one eye is not worth coaching a game in the NFL. You have to look out for your long-term health,” Spielman said. “That’s the No. 1 thing everyone’s worried about.”

Spielman would not say whether there is potential for Zimmer to miss multiple games. The team will reassess the situation Friday morning.

“We have to see how his eye responds to that surgery,” Spielman said.

Despite having a pair of former NFL head coaches on staff in offensive coordinator Pat Shurmur and offensive line coach Tony Sparano, Zimmer and Spielman agreed that Priefer, who has coordinated the Vikings’ special-teams units since 2011, was the least disruptive interim option.

“I believe that at this time, for this game, the best scenario is to have everybody do their roles, because Pat has spent all week getting the offense prepared and George Edwards has spent all week with the defense,” Spielman said. “We have the utmost confidence in Mike Priefer that he will be able to handle the interim head coaching duties tonight.”

Kickoff for Thursday night’s game at U.S. Bank Stadium is scheduled for 7:25 p.m.