Should Raiders target Sheldon Richardson, Muhammad Wilkerson?

Sheldon Richardson's pass-rush skills have been dormant in recent seasons but could be reinvigorated in Oakland. David Rosenblum/Icon Sportswire

ALAMEDA, Calif. -- Did Jon Gruden tip his hand a tad at last week's NFL combine by saying that Bruce Irvin is at his best as an edge rusher, rather than as an outside linebacker in coverage, when it comes to the Oakland Raiders' plans in the draft and free agency?

If so, that could mean a position switch for Irvin, which would open up a need for the Raiders at outside linebacker.

Beyond that, Gruden said Irvin could use "some help so he can do the things that he does the best, more often." That might mean adding a pass-rushing interior defensive lineman.

And somewhere, Khalil Mack -- who eats a steady diet of double- and triple-teams every game -- is smiling, too.

Because while defensive tackle Justin Ellis -- a fourth-round draft pick of the Raiders and 2014 draft classmate of Mack's -- is solid against the run, he is also a free agent. He has only a half-sack in his 60-game career, which came in last season's opener at Tennessee. Plus, last year's third-round pick, Eddie Vanderdoes, is coming off surgery to repair a torn ACL and did not have a sack in 16 games, 13 of which he started.

The Raiders' draft plans will no doubt be influenced by what they do in free agency first, what with the new league year beginning March 14 and the draft not commencing until April 26.

Whom might Oakland target first in free agency to address an interior defensive push?

Keep in mind that the Raiders currently have about $16.3 million in salary-cap space, per ESPN Stats & Information, and they still need to sign Mack to a contract extension. They can get $8.5 million more in cap space by releasing cornerback Sean Smith and still have to make decisions on whether to re-sign middle linebacker NaVorro Bowman, cornerback TJ Carrie and defensive end Denico Autry.

It isn't as if Oakland general manager Reggie McKenzie, not known as a huge spender anyway, would break the bank for any of the top three defensive tackles on the market.

But just for spit and giggles ...

Sheldon Richardson is ESPN's No. 6-ranked overall free agent on the market in an Insider post. Although he has only 2.5 sacks the past two seasons, a fresh start in Oakland might rejuvenate him and cause him to flash like he did his first three seasons. That's when he had 16.5 sacks, with eight coming in 2014. Plus, as Pro Football Focus notes, he has averaged 43 total pressures the past three seasons, so he is collapsing the pocket.

Then there's Star Lotulelei, whom many think Oakland should have drafted in 2013 instead of cornerback DJ Hayden. Lotulelei, ranked by ESPN as the No. 9 free agent, has 11.5 sacks in his career, including four in 2016.

Dontari Poe is the No. 12-ranked free agent by ESPN. The Raiders are more than familiar with his work, what with him having played the first five seasons of his NFL career with the AFC West rival Kansas City Chiefs. He has 15.5 career sacks, and his 745 snaps last season were second-most on the Atlanta Falcons' defensive line.

What about the draft? What if the Raiders do not address the interior of the D-line in free agency?

The Raiders have consistently been linked to linebackers (Georgia's Roquan Smith and Virginia Tech's Tremaine Edmunds) and cornerbacks (Ohio State's Denzel Ward and Iowa's Josh Jackson) in mock drafts.

But what if Washington defensive tackle Vita Vea is still sitting there at No. 10 for Oakland?

Vea is a physical freak athlete at 6-foot-4, 347 pounds, while running the 40-yard dash in 5.11 seconds at the combine and bench-pressing 225 pounds 41 times.

Here's an idea: Oakland signs free-agent defensive end Muhammad Wilkerson, ESPN's 23rd-ranked free agent, and his 44 career sacks and also drafts Vea to pair with Irvin and Mack.

Intimidating thought, no?

"Obviously, defensively, there are some glaring needs at this time," Gruden said at the combine when asked what he sees as the biggest need on the roster. "Free agency hasn't started yet, but our linebacking corps, we have a lot of unknowns there. NaVorro Bowman is a free agent, looking for an inside pass-rusher to step up.

"Our secondary, we have to clean that up. I think most importantly with the Raiders, just looking at our last three drafts, we need some young people to emerge and start playing -- a lot -- for this football team."