The old adage is, "Build a team from the inside out, front to back. " Those two rules intersect at the Center. That's the first position you have to get right. I believe a great deal of the O-line's problems this year had to do with inferior center play, which spilled over to the guards, which affected the tackles, yada yada yada. So upgrading there is Job One as I see it. Problem is, it's rare a rookie makes a huge impact right off the bat at Center so the Bills would have to be prepared to live with a learning curve. The alternative is to sign a FA center. In any case, a better than average Center is crucial.