Dallas Cowboys guard Zack Martin has tested positive for the coronavirus, head coach Mike McCarthy told media on Sunday, and has been placed on the reserve/COVID-19 list.

Martin has been ruled out for the Cowboys' first game of the season, Thursday's contest against the Tampa Bay Buccaneers.

Via the Dallas Morning News, McCarthy said Martin is “frustrated, obviously. But this is the world we live in.” McCarthy also said that Connor McGovern will be starting in Martin's place.

Martin, a six-time Pro Bowler, is a significant loss for the Cowboys. He was looking to get back on track after a calf injury and concussion limited him to 10 games in 2020. It was also the first time in his seven-year career that he missed the Pro Bowl.

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It's unclear how much time Martin will miss. Since he has tested positive, everything hinges on when he'll begin testing negative. If he's unvaccinated, he'll have to miss at least 10 days, and possibly more if he continues to test positive. If he is vaccinated, he can return to the team once he tests negative twice in 24 hours.

Offensive lineman Brandon Knight was determined to have been in close contact with Martin and has also been placed on the reserve/COVID-19 list. As an extra measure of caution, the Cowboys conducted their Sunday meetings virtually.

"They're just trying to contain, make sure that we're doing our due diligence with the COVID protocol procedures," McCarthy told reporters via the Dallas Morning News.