Under sunglasses and a cloudy sky, Vikings coach Mike Zimmer addressed what the team called a “minor medical procedure” that led to a canceled news conference Tuesday.

Zimmer, 60, had a procedure done to fix a torn retina in his right eye after scratching it during the Vikings’ 20-10 loss to the Bears on Monday night.

“First of all, I’d like to apologize for not being here yesterday,” Zimmer said. “I had some trouble with my vision for a couple days, and during the game, I scratched on my eye. So, the doctors, after the game, they checked and had me get in for an appointment and I found out that I had a torn retina.”

Two Edina-based ophthalmologists, Dr. David Williams and Dr. Scott Sanderson, performed the procedure, Zimmer said. He was at the team’s headquarters Tuesday afternoon and spent the night at Winter Park before offensive coordinator Norv Turner notified him of his resignation at 6:30 a.m.

“They said if you don’t take care of those things that you have a possibility of going blind,” Zimmer said. “So, that’s why I wasn’t here.”

Although medical professionals might not recommend staring at a computer, Zimmer wasn’t deterred from his film study.

“I’ve been watching film with one eye all week or whatever it is,” Zimmer said. “I’ve had to wear reading glasses, so I can write because I can’t see out of my right eye. Fortunately, it’s probably a good thing I scratched my eye during the game, otherwise I probably wouldn’t have caught it in time. But hopefully everything will all right.”

No excuses

The Vikings’ third starting left tackle of the season, Jake Long, hasn’t made any excuses about his play, though there are a handful.

Long made his first start in two years Monday and was one of four different offensive linemen to allow a sack on quarterback Sam Bradford. The 31-year-old is working his way to game speed after playing sparingly over the past two seasons.

“I feel better and better as I get more time,” Long said. “There’s no excuses. I got to get up to speed quickly. I just have to keep getting better.”

Guard Brandon Fusco also called himself out for a poor game against the Bears.

“I didn’t play well enough on Monday night,” Fusco said. “I think I physically just got beat. You guys saw, got ran over a couple times and that’s on me. Just have to man up.”

Injury report

• Jerick McKinnon is hopeful to play Sunday against Detroit after an ankle injury kept the running back out of Monday night’s game. “Right now, it’s looking good,’’ he said.

McKinnon, however, still wasn’t able to practice Wednesday. He jogged and stretched in warmups with the team before observing practice drills.

• Three Vikings are in the concussion protocol and were among six players unable to practice Wednesday.

Guard Alex Boone (concussion/shoulder/knee), linebacker Eric Kendricks and defensive tackle Tom Johnson are recovering from brain injuries. Mc- Kinnon, guard Zac Kerin (hand) and defensive tackle Sharrif Floyd (knee) also did not practice. Cornerback Captain Munnerlyn, who underwent X-rays after the game on a foot, said test results showed he’s “good.” He was limited in practice.

• Safety Andrew Sendejo (knee) and punt returner Marcus Sherels (wrist) returned to practice after sitting out in Chicago.