Coach Mike McCarthy confirmed Lawrence has a broken foot and underwent surgery Thursday. He didn't offer an exact timeline for his return but said "he'll miss significant time."
McCarthy said Thursday that Lawrence was hurt on a one-on-one pass rush move coming around the corner in Wednesday's practice.
"Obviously, losing DeMarcus, he's a prime-time player for us. I thought he had a nice start in Tampa," McCarthy said. "You hate to see these injuries to any of your guys, but what it does is it gives opportunities to the other players. How we will spread that out will be done through game plan. We'll work on that today, tomorrow and Saturday. Specifically, we'll get into that when we play the game."
"His tenacity and energy and he plays with is what you will miss," McCarthy said.
It is a giant blow to a defense that did not generate a sack in Week 1 against the Tampa Bay Buccaneers and could also be without its second-best pass rusher, Randy Gregory, on Sunday against the Los Angeles Chargers.
Lawrence was listed as a limited participant in Wednesday's practice but immediately had an MRI, which revealed the break. Lawrence did not practice for most of training camp because of offseason back surgery, but he recorded six tackles, two quarterback pressures and forced a fumble against the Buccaneers. He has 45.5 sacks for his career and is a two-time Pro Bowl pick.
Lawrence tweeted on Wednesday that he "will be back & ready."
As for Gregory, McCarthy did not sound hopeful before practice about him passing COVID-19 protocols in time to play against the Chargers.
"If you look at the history, it's been 10 days pretty much everybody we've dealt with in the COVID protocol," he said Wednesday. "We'll just see how it goes."
With Lawrence out and if Gregory cannot play, then the Cowboys would potentially turn to Dorance Armstrong and Tarell Basham as their starters at defensive end with Bradlee Anae and Chauncey Golston as backups. They have combined for 10 sacks in their careers, or only 3.5 sacks more than what Lawrence recorded a year ago. Basham has 7.5 sacks in 59 games.
Golston, a third-round pick in this year's draft, missed all of training camp with a hamstring injury and was inactive for the season opener.
Perhaps the start of Wednesday's practice was a bad omen for the Cowboys' defensive line. Assistant defensive line coach Leon Lett was carted off the field with a torn quadriceps on Wednesday and underwent surgery on Thursday.
Since the 31-29 loss to the Buccaneers, the Cowboys have lost four starters: Wide receiver Michael Gallup was placed on injured reserve with a calf strain, right tackle La'el Collins was suspended five games for violating the NFL's substance abuse policy, Gregory was placed on the reserve/COVID-19 list and now Lawrence is out with the broken foot.