By Danny O'Neil
RENTON – The uncertainty is unexpected considering Seattle's defense returns all but two starters.
However, don't mistake a lack of turnover for stagnancy as the uncertainty of the pecking order for that defense might be one of the most intriguing things about training camp.
There's an oft-injured cornerback trying to make the decisions as difficult as possible for the coaches, three different players in the running to be Seattle's run-stuffing defensive tackle on early downs and a former running back trying to make the team as a linebacker.
That's quite a bit of drama for a defense that returns largely intact after allowing the fewest points in the league last year, and with Seattle playing its first preseason game on Thursday in San Diego, let's sketch out the most compelling battles on the defensive depth chart:
I. Cornering the market
Walter Thurmond is making a compelling case to be the fifth defensive back in Seattle's nickel defense ahead of Antoine Winfield. Thurmond is also getting a chance to audition at starting cornerback, taking a healthy chunk of the first-team repetitions on Monday while Brandon Browner watched.
Thurmond is showing the playmaking ability that has inspired such high hopes for him in Seattle since the Seahawks drafted him in the fourth round in 2010, when he was coming off a knee surgery his senior year at Oregon. That's just part of the injury history that looms in the background for Thurmond. In a single 18-month span from 2011 to 2012, he suffered a high ankle sprain, strained a hamstring and broke his leg twice, finishing each of the previous two seasons on injured reserve.
It's one thing for Thurmond to play his way into a role, and another for Seattle to make long-term roster decisions on the presumption Thurmond will stay healthy. Cornerback is the deepest position on this team, and Jeremy Lane and Byron Maxwell have been impressive in training camp, too, but the competition for roles at the top of the depth chart may be even more compelling than the battle to be one of the cornerbacks on the 53-man roster.
II. Tackle a question
The Seahawks drafted Jordan Hill in the third round out of Penn State because of his ability to provide interior pass rush, but Seattle also needs a run-stuffing tackle on early downs and there are a number of candidates. The Seahawks didn't just sign Tony McDaniel to replace Alan Branch at defensive tackle, they drafted Jesse Williams from Alabama with an eye for that opening, too, and then there's Jaye Howard, last year's fourth-round pick, who's bigger and trying to start fresh this second season.
This competition is still wide open. McDaniel is the tallest player on the team, someone who can't help but stand out, but he has started four games in his seven NFL seasons. There are questions about Williams' durability as he sat out three of the team's first seven practices, though just when you thought his sore knee might undermine his rookie season, he stood out in the simulated game last Friday. Then there's Howard, whose rookie season out of Florida was pretty much a total wash. Coach Pete Carroll said Howard will get some time with the first-unit defense, and this is the time for him to make a move on the depth chart if he's going to claim a role.
III. Mystery in the middle
No doubts about Seattle's starting middle linebacker. That's Bobby Wagner, who was the runner-up as the Defensive Rookie of the Year last season. But behind him? That's a good question. On one hand, there's Heath Farwell, a special-teams mainstay who has experience at linebacker. On the other, there's Allen Bradford, who was a running back when the Seahawks claimed him off waivers from Tampa Bay in October 2011, but he's now at linebacker.
There are still some rough edges for Bradford, who is still feeling his way at the position, but he's also got a lot of potential. In scouting terms, Bradford has more upside, but he's going to have to show he's not a liability despite the fact he has less than two years of experience playing linebacker. He's someone to watch in San Diego because if he can learn the fundamentals, he's got the speed and size to be a true prospect, but he's going to have to turn it on.