Dallas Cowboys guard Zack Martin will miss the team's season-opening game on Thursday vs. the Tampa Bay Buccaneers after testing positive for COVID-19. According to running back Ezekiel Elliott, that means the Cowboys will be without their best offensive player. 

"Zack's our best player on our offense. I mean, most runs, they coming back behind him," he told reporters Monday. "It's disappointing, but you can't harp on it, can't let it be more than what it is. I mean, definitely going to miss him, definitely wish he was out there, but we still have a game to go play and we got to try and get the job done."

Elliott's assessment of Martin might surprise some people on an offense loaded with stars at the skill positions like himself, Dak Prescott and Amari Cooper. But it was Martin who was the highest-ranking Cowboy on Pro Football Focus' ranking of the top 50 players in football this summer, coming in at No. 13. 

As Sam Monson wrote, "The Dallas offensive line fell apart last season, but Martin was still playing his best football right up until getting injured, even when he kicked out to right tackle. Martin earned a PFF overall grade of 91.3 at the time of his injury, allowing just 13 total pressures across 10 games. He has now allowed just one sack in two years for the Cowboys."

So Martin's absence on Thursday against the defending Super Bowl champions—he's reportedly vaccinated, but still requires a five-day absence in the league's return-to-play protocols—is a major loss for a Cowboys team with major aspirations of their own this season.