Minnesota Vikings quarterback Kirk Cousins has tested positive for COVID-19 and will be unavailable to play in Minnesota's preseason opener on Sunday against the Las Vegas Raiders, head coach Kevin O’Connell announced Friday. 

Cousins was sent home from the Vikings' practice facility on Thursday with an undisclosed illness. The positive test means that he will be required to quarantine for five days before being allowed to return to the team. 

Minnesota Vikings quarterback Kirk Cousins at training camp

Minnesota Vikings quarterback Kirk Cousins takes the field during the first day of training camp at TCO Performance Center in Eagan, Minnesota, on July 27, 2022. (Nick Wosika/Icon Sportswire via Getty Images)

"He's feeling pretty darn good and has limited symptoms," O'Connell said, according to the Vikings' website. "He's wearing me out about the install this morning, and the plan for Sunday. Unfortunately, he will not make the trip.

BALTIMORE RAVENS EXTEND RECORD PRESEASON WINNING STREAK AGAINST TENNESSEE TITANS

"He should, by the protocol standards, be back by Tuesday morning and ready to roll for our Niners [joint] practices," O'Connell added. "As always, we'll keep you guys posted."

Vikings quarterback Kirk Cousins after beating the Bears

Minnesota Vikings quarterback Kirk Cousins is interviewed by NFL sideline reporter Ben Leber after a 31-17 win over the Chicago Bears at U.S. Bank Stadium in Minneapolis, Minnesota, on Jan. 9, 2022. (Adam Bettcher/Getty Images)

In March, the NFL paused its COVID-19 protocols, ending the mandatory testing of players as well as masking in team facilities. 

PATRIOTS’ BILL BELICHICK ADDRESSES OFFENSIVE PLAY CALLING DUTIES: ‘DON’T WORRY ABOUT THAT’

"I like the way he handled it — reporting the symptoms and just going through the in-house process that we have here," O'Connell said. "I'm proud of the way [he] did that — ultimately looking out for his teammates — and we'll get him back and ready to roll as soon as possible."

HOME OF EX-SEAHAWKS STAR EARL THOMAS DESTROYED IN FIRE: REPORTS

The Vikings will now turn to their two backup quarterbacks, Kellen Mond and Sean Mannion. Mond is entering his second season in the league after being drafted by the team in the third round of the 2021 NFL Draft. Mannion has been with the Vikings since 2019 after spending his first four years with the Los Angeles Rams. 

Vikings quarterback Kirk Cousins at training camp

Minnesota Vikings quarterback Kirk Cousins looks to pass during the first day of training camp at TCO Performance Center in Eagan, Minnesota, on July 27, 2022. (Nick Wosika/Icon Sportswire via Getty Images)

CLICK HERE TO GET THE FOX NEWS APP

"We'll figure out a good game plan for those guys," O'Connell said. "No matter who starts, they're both going to play a ton. A big evaluation game for us for those two guys. They've done a lot of really good things in camp, and now we get to watch them play against a [different] defensive structure, different coverages. I think it'll be really good for those guys."

CLICK HERE FOR MORE SPORTS COVERAGE ON FOXNEWS.COM

The kickoff between the Vikings and the Raiders is scheduled for 4:25 p.m. ET on Sunday.