Should Raiders target Sheldon Richardson, Muhammad Wilkerson?

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 at outside linebacker.

And beyond that, Gruden also 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…