It's been awhile so I'll refresh your memory: Seattle was awful in 2006. Playing one of the top five easiest schedules in the league, Seattle was outscored by its opponents. Only luck and the golden foot of Josh Brown pushed Seattle into the playoffs, and only luck and the bumbling of Tony Romo kept them from a first round exit. The offense was injured all over and never properly replaced left guard Steve Hutchins, but the defense was healthy. Outside safety, only Chartric Darby started fewer than fifteen games, starting fourteen, and didn't miss time due to injury, but lack of injury. The two games Darby started on the sideline were the two games Marcus Tubbs started. Tubbs was fresh off a season he looked every bit the defensive tackle we now see in Albert Haynesworth, and the surrounding front seven - small, fast, smart and full of hustle - thrived around its giant keystone talent.
Tubbs will never start again in the NFL. Seattle unearthed a gem in the 2007 draft, drafting defensive tackle Brandon Mebane in the third round. Like too many deserving talents, Mebane sat behind a nearly useless veteran, Darby, and started only after a fortuitous injury. Mebane became that rare talent that consistently forced double teams, and could get after the quarterback. Seattle's defense took off after his arrival.
With Rocky Bernard likely lost to free agency, Seattle faces starting Craig Terrill at left defensive tackle. Terrill is cheap, nearing 29, and a good situational one-gap tackle that is too slight and too weak to be useful on most downs. Inevitably, teams will simply run at Terrill, and as lead blockers breach the second level, Seattle's exceptional group of linebackers, each capable of exploding into a ball carrier from almost any point on the field to almost any point on the field, will be blocked into the turf and made spectators to their own humiliation. Deon Grant and Brian Russell won't stop the mayhem and like those 2006 Seahawks, rushing yards will come in bunches. For all its talent, the defense will fold against power rushing.
Seattle needs someone who can start at left defensive tackle. It drafted Red Bryant in 2008, but Bryant looked awful at times at Texas A&M and in the preseason, and missed all but four games because of injury. High ankle sprains can be reoccurring and his knee injury wasn't his first. It's far too early to give up on the very talented Bryant, especially entering a season the Seahawks should not expect to compete, but it's unwise to count on him either. Regardless of Bryant's health, Seattle needs another defensive tackle in its rotation and an upgrade on the large, slow, but anything but stout Howard Green.
Seattle could add talent through the draft. B.J. Raji is a huge reach at four and does not fit Seattle's preferred player profile. Peria Jerry will be 25 before his first season in the NFL, meaning he was very old for his level. Jerry also slots somewhere between Seattle's early first and early second round picks. Sen'Derrick Marks disappointed in 2008, but is more than three full years younger than Jerry. Marks must overcome questions about his work ethic, but is the most complete run/pass defensive tackle in the draft. He's an exciting athlete and potentially the best value in the draft, but not likely a day one contributor and not "starting capable". Ziggy Hood splits the difference between Jerry and Marks, as young as Marks, but as accomplished as Jerry. Hood is a straight line guy. He bursts off the snap, shows impressive hand fight techniques, but is easily eluded by lateral moves. That may not be a problem on a Seahawks team replete with quick, agile defenders in its front seven. Should Hood reach his potential, he'd present a matchup nightmare alongside Mebane. Two tackles requiring double teams, each capable of aborting run plays or sacking the quarterback if single blocked.
The alternative is signing a free agent retread. Shaun Cody should be very cheap, but his struggles are real and one wonders if he's really more valuable than a no-name toiling on another team's practice squad. Albert Haynesworth is mega-expensive and explosively violent. It's possible Seattle simply can't afford him and probable Ruskell wants nothing to do with him. Jovan Haye is a very good one-gap tackle that could function as a situational end, but isn't stout against run and presents many of the same problems as Terrill. Chris Canty is mega-expensive (or thinks he should be) and better suited for a 3-4. Haye or Cody makes the most sense. Either could start and neither buries Bryant if he breaks out. Hood and Marks are the most exciting.