The team was already expected to be without starting defensive end Chris Clemons, who is recovering from knee surgery and could miss part of the season. Backup defensive end Greg Scruggs could miss the full season after suffering a knee injury more recently.
2012 Sacks for Current Seattle DL
Seattle was already expected to alter its rotation after adding Cliff Avril, Michael Bennett and Tony McDaniel through free agency, plus defensive tackles Jordan Hill and Jesse Williams through the draft.
Veteran linemen on the Seahawks' roster combined for 43.5 sacks last season. Clemons (11.5), Irvin (8.5) and Scruggs (2.0) combined for 21.5 of them, or 49.4 percent. At least two and probably all three won't play early in the season.
Seattle's veteran defensive linemen combined to play 4,767 snaps for their teams last season. Players responsible for playing 3,317 of those snaps -- 69.6 percent -- remain available.
The picture changes if we consider only the three players best suited to fill the "Leo" defensive end position in coach Pete Carroll's defense. Avril, Clemons and Irvin are those three players. Clemons and Irvin combined to play about two-thirds of those snaps. The team doesn't necessarily have to play defense exactly the way it played defense last season. At this rate, that might not be an option, anyway.
Seattle's current defensive linemen combined for 16 sacks on third down last season. The currently unavailable Irvin (5.5), Clemons (4.5) and Scruggs (1.0) combined for 11 of them. Bennett (3.0) and Avril (2.0) had the other five.