No defense has more talent under expired contracts than the Cardinals: Calais Campbell, Frostee Rucker, Chandler Jones, Kevin Minter, D.J. Swearinger and Tony Jefferson are all free agents, and some of them will have to be replaced externally. But things are even more dire along the interior offensive line. Left guard Mike Iupati (who had a poor season) is the only usable returning piece. Center A.Q. Shipley's deal is up; guards Evan Mathis and Earl Watford also enter free agency (and they're both replaceable). Arizona runs a lot of empty formations, with no one in the backfield to help protect QB Carson Palmer. It's imperative that the core of this line be strong.