The Ravens have already lost two defensive linemen to season-ending injuries, and nose tackle Terrence Cody remains sidelined after hip surgery.
That doesn't leave much depth behind veteran starters Chris Canty and five-time Pro Bowl pick Haloti Ngata in the Ravens' 3-4 scheme. Brandon Williams is expected to become the starting nose tackle, with Ngata shifting to defensive tackle. That spot was held last year by Arthur Jones, who signed with the Indianapolis Colts as a free agent.
The only other defensive lineman on the roster with any experience is DeAngelo Tyson, a third-year reserve who had 10 tackles, two sacks and an interception last season.
The Ravens took two defensive linemen early in this year's draft, selecting Timmy Jernigan in the second round and Brent Urban in the fourth. Jernigan should play right away as a backup, but the 6-foot-7 Urban is out for the season after suffering a torn ACL. The Ravens also will be without Kapron Lewis-Moore, a second-year defensive end who ruptured an Achilles tendon in camp last week.
Both Urban and Lewis-Moore were expected to contribute, which should have helped Canty and Ngata, both in their 30s, stay fresher over a 16-game season. Canty and Ngata each missed one game last season.
One possible short-term solution is moving outside linebacker Pernell McPhee back to the defensive line. He started six games there two years ago.
"He's a potential answer there," coach John Harbaugh said. "So is DeAngelo Tyson. Those guys have to play all the positions, so you end up rolling guys around. Your first answer for any type of depth issue is the guys you got on your team. They need to step up, and they are more than eager to do that."
Early returns this preseason, particularly against the run, have been mixed. San Francisco running back Carlos Hyde averaged nearly 8 yards a carry in limited work against the Ravens starters in the preseason opener. Then against Dallas, the Ravens returned a fumble for a touchdown and held the Cowboys to 3.6 yards a carry in the first half.
The Ravens host the Washington Redskins on Saturday night.
For years while Ray Lewis and Ed Reed patrolled the field, defense was the Ravens calling card; they ranked in the top 10 every year from 2003-2011. Five times in that span they ranked in the top three. They slipped to 17th in 2012 and ranked 12th last year.
The Ravens were outscored 134-115 in the fourth quarter last year and at times struggled to get a key stop late in games.
Despite the injuries, defensive coordinator Dean Pees is hoping they can return to that elite level.
"The sky is the limit, " Pees said. "We have to execute. . But I really feel like we can be as good as we want to be."