Mike Zimmer listened to the Vikings lose to the Dallas Cowboys on the radio from his house Thursday night, and it’s unclear when the head coach will rejoin his team.

Zimmer underwent emergency eye surgery late Wednesday night to repair a detached retina in his right eye. After a follow-up appointment with doctors Thursday morning, it was decided that Zimmer needed to get some rest and that special teams coordinator Mike Priefer would coach Thursday.

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

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

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

The team canceled Zimmer’s regular day-after news conference scheduled for Friday afternoon.

Zimmer’s latest surgery was the third on his right eye in the past month. The third-year coach had been scheduled to undergo the third surgery Friday morning 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 Zimmer was examined by the doctors it was determined that he needed a more significant third procedure to ensure that the coach’s condition didn’t worsen.

Zimmer, 60, first underwent a procedure to fix a torn retina Nov. 1, a day after scratching his eye 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.

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

In most cases, people don’t even know they have torn their retina until they go in for a routine eye exam, said Aaron Shukla, associate professor and director of the ophthalmic technician program at St. Catherine University.

Small tears usually don’t cause vision problems, but larger tears can cause people to see flashing or “floaters” that look like little insects flying by. Tears, which can be the result of aging, medical conditions or trauma, need to be repaired because they can lead to a detached retina, Shukla said.

In the case of a detached retina, Shukla said “it needs immediate surgery or you risk blindness,” adding that it’s a major operation done in a hospital.

Shukla said recovery from surgery can vary from a week to up to six weeks. “It all depends on where the detachment was and how large,” he said.

Whether Zimmer will be able to board an airplane and be on the field for the Vikings’ game Dec. 11 in Jacksonville will be up to his doctors, Shukla said.

Most often one repair surgery fixes the problem but sometimes it can require “multiple surgeries,” he said. Once healed, the prognosis is good, Shukla said. Many patients can regain full 20/20 vision or close to it.

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

“Potentially going blind in one eye is not worth coaching a game in the NFL,” Spielman said.

Despite having a pair of former NFL head coaches on staff in interim 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 for Thursday.

But beyond that game, there is little clarity about who will be leading this team Tuesday morning, when the Vikings begin their preparations for their trip to Jacksonville next weekend.

Staff writer Mary Lynn Smith contributed to this report.