We now move to the defensive side of the ball which is far more in need of upgrading than the offense. But even with the many players who should not be back, there are some who should remain to help build the unit next season. After all, they can't do yet another complete overhaul and expect to improve from last season. You keep what works and toss what doesn't in favor of an upgrade.

Here are the Raiders free agents on defense and where the Raiders' priority should lie.

DT Vance Walker UFA

Came to the Raiders last off-season on a one-year "prove it" deal. He had some good games last season but didn't quite show he is standout starter material. the team could very much stand to upgrade his position.

Verdict: Low priority

S Charles Woodson UFA

The 16-year veteran has said he would like to spend one more season with the Raiders before hanging up his cleats. He was an iron man this year at 37 years old, starting every single game at free safety. His veteran leadership has been invaluable to the young players on this team. It would also be a great thing watching him play his last games in Silver & Black and get a proper send-off from a Hall of Fame career.

Verdict: High priority

DT Pat Sims UFA

Outplayed expectations, starting every game this season and playing the bulk (so to speak) of the snaps at the DT/NT spot. He proved he can carry the load over a full season with strong run stopping abilities as well as some power to get into the backfield. Keeping him around would mean one less major need either in free agency or the draft.

Verdict: High priority

CB Mike Jenkins UFA

When the Raiders signed him to a one-year deal last off-season, he was the last cornerback on the market who even resembled a starter. He didn't much resemble a starter this season with the Raiders and the team enters another off-season desperate to upgrade the cornerback position.

Verdict: Low priority

CB Tracy Porter UFA

The only thing worth shouting about among the Raiders corners was in anger and confusion. That being said, Porter had some good moments here and there in coverage and led the team in passes defended. He also showed the versatility to play both the boundary as well as the slot.

Verdict: Moderate Priority

DE Lamarr Houston UFA

What began as a great season by Lamarr plateaued a bit near the end of the season. The team had been working on re-signing him all throughout the season but couldn't get a deal done. The hope is now that the team has more money to spend and Houston maybe didn't quite play up to the contract for which his agent was holding out, the two sides can get something done. He seemed distraught at the end of the season about his prospects of returning but Dennis Allen said he is still in the plans. Lamarr had a career best 6.0 sacks and led all 4-3 defensive ends with 54 solo tackles.

Verdict: High priority

DE Jason Hunter UFA

Signed to a one-year deal and was the weak link on the defensive line.

Verdict: Gone

S Usama Young UFA

Another one-year deal player, he has familiarity with Dennis Allen and played quite well in limited duty. His not starting over Brandian Ross was one of the great mysteries of this season.

Verdict: Moderate priority

CB Phillip Adams UFA

In 2012, he looked like he could break out if he could stay healthy. In 2013 he showed why he never has.

Verdict: Low priority

CB Chimdi Chekwa RFA

Plays a nice bit of special teams and can fill in at corner in a pinch. But as a starter, he was abused by opposing quarterbacks. Peyton Manning saw Chekwa on the field and took whatever he wanted, whenever he wanted it.

Verdict: Low priority

DT Daniel Muir UFA

The 7-year veteran defensive tackle was signed in the early part of the season. Every time he was put in the game, he gave the defense a shot of energy. And he is a great locker room guy too. They need to bring in some upgrades at the position but Muir could be solid depth.

Verdict: Low priority

The Raiders also have two Exclusive Rights Free Agents on defense in LB Kaelin Burnett and S Brandian Ross. Both are expected to be back to compete for a roster spot.

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