The Seahawks have shown interest in defensive backs again this season even after taking three last year in the Draft, signing several UDFA DBs, and adding a first-year Pro Bowl corner in Brandon Browner. So, at the moment, the Seahawks secondary includes Earl and Kam at safety, Walter Thurmond as the assumed nickelback, Brandon Browner and Richard Sherman at corner, then Byron Maxwell, Ron Parker, Chris Maragos, Jesse Hoffman, Phillip Adams, Coye Francies, Jeron Johnson, and exclusive rights free agent Kennard Cox to duke things out for the remaining time and roster spots.
While it's probable that Walter Thurmond will play the nickelback role in a lot of the Seahawks' looks, the team still may be looking for another talented DB or two in the later rounds to compete with this group and I still think the Seahawks want a big nickel player like Atari Bigby from last year to emerge from the group. The need to better match up with teams' two tight end looks and improve in coverage against that and the speedier running backs - and this means corner/safety hybrids are in demand.
They've shown now shown at least some interest, met with, attended pro days or planned workouts with later round defensive back prospects like Janzen Jackson, Ron Brooks, Desmond Marrow, and now Jeremy Lane, according to twitter and other sources. Though attending meetings and pro days don't necessarily imply interest, it would make sense if the Seahawks wanted to look at defensive backs later in the draft after hitting on Sherman and Chancellor the last two seasons.
Ron Brooks measured in at 5'10, 190 at the Combine and ran the 40 in 4.35 seconds and had a 38" vert. His stock is kind of all over the board, from a late rounder in some lists to a 3rd or 4th rounder in others.
I do know too, from asking him on Twitter, that the Seahawks also attended the Pro Day of Toledo's Desmond Marrow, and he talked to them afterwords. Marrow is an intriguing prospect at 6'2, 210 that can play either safety or corner, and with his size could theoretically play that 'big nickel' position that has become more important in recent seasons. He's fast and athletic, and could be an option in the later rounds.
Finally - Northwestern State's Jeremy Lane apparently has a visit lined up with the Seahawks. Lane is 5'11, 175, with speed and athleticism. He's good in zone and is another potential target to upgrade the secondary.