Now how about O Line?

We need a replacement for Richie Incogito and Alex Barron will more than likely be gone after this year. With the injuries that the offensive line has sustained the past three years it wouldn't hurt to start adding some depth. I'm a big fan of Mike Iupati but somehow, I don't think he will be there for round two. How soon do we want to start drafting O Line talent? Round two? Day two?