Both Dennis Allen and Reggie McKenzie are widely known as defensive-minded guys, yet they used their first draft pick as Raider head honchos on an offensive lineman. This may have been a surprise to those who follow the team, knowng what a cesspit of horrors the defense was last year, but McKenzie stayed true to his board. He didn't reach, he didn't panic, he took the player he wanted and fulfilled a huge need- depth on the offensive line.
That being said, even with McKenzie filling all the starting roles on defense through free agency, defensive depth and talent is still a huge issue that must be addressed. A number of McKenzie's signees are on one year deals, and the Raiders will be able to save money if McKenzie can draft potential starters in the upcoming late rounds rather than shelling out big bucks to veterans.
Linebacker is a huge need, especially if the team moves to a base 3-4 defense or even if it incorporates a mixture of 4-3 and 3-4 concepts. That will require at least six good linebackers, and the Raiders have approximately two, or three if Travis Goethel returns to form from his injury. Philip Wheeler is a good player, but more is needed. I expect the Raiders to make a run at a guy like Josh Kaddu, Ronnell Lewis or Alex Hoffman-Ellis.
Cornerback is another area of need. Shawntae Spencer and Ron Bartel are the de facto starters, but behind them is only Demarcus Van Dyke and Chimdi Chekwa. More depth and talent is required. Alfonzo Dennard and Chase Minnifield are still on the board, and Cliff Harris would be an interesting pick later on in the draft.
Defensive tackle is also an area of concern, as the Raiders lack the true nose tackle that is the keystone to a 3-4 scheme. Josh Chapman is currently on the board, as is Mike Martin and Alameda Ta'amu. One of these guys would be an excellent investment for the team, as Richard Seymour isn't getting any younger.
The Raiders could go any number of ways, but as long as they remain true to their board and pick the player they feel is best for the team, the Raiders will improve regardless due to what we hope is superior coaching and leadership.