While a lot of focus is on what the Titans will do on the second level of their defense, the defensive line still has its fair share of questions. There is no better place to start with those questions than who should start at NT.
Whether you call it NT or the 1-technique (I realize the differences) the Titans need an anchor in the middle of the DL that can hold the point of attack in the run game, while pushing the pocket on passing downs. I think the dark horse candidate for this job is Mike Martin.
Martin doesn't posses ideal height or bulk, but he is obscenely strong for his size and he isn't someone that offensive linemen can just push around. While Sammie Lee Hill and even Jurrell Casey can make the argument that they should be in the middle on passing downs, I think on an every down basis Martin has to be the guy. While the former DTs posses quick feet and know how to penetrate, they don't always maintain gap integrity and can get so focused on making the splashy play that they forget their responsibility.
Even if the Titans bring in someone like Notre Dame's Louis Nix (if he falls to round two) or Tennessee's Daniel McCullers (on Day Three) I think that Martin should be at least given a chance and at the very least should be the primary backup.