After the earlier look at offensive tackles by Pro Football Focus, it's time to look at their article on the guards and centers in pass protection. Green Bay Packers RG Josh Sitton really stood out, as he has done all offseason, coming in at No. 5 overall among guards. From PFF:
Elsewhere in the top five there is the guy recognized by many as the league’s top guard, Logan Mankins, and a Packer whose excellence seems to be really catching on in Josh Sitton.
While that's outstanding work by Sitton, the article doesn't mention two other players who started all 16 games (plus postseason) for them: LG Daryn Colledge and C Scott Wells. The article doesn't rank all guards (only the top 20 and bottom 20) or centers (only the top 10, bottom 10), and both players fall somewhere in the middle. That's a good assessment: average, reliable players.
The Packers should be thinking about keeping Sitton long-term, though he won't be a free agent for at least another year (depending on the new labor rules). If he keeps it up for another year or two, he could become the highest paid guard in the NFL. They should also see they have something good in Colledge and Wells, who are both average players that are rarely injured. They shouldn't be overpaid, but I expect the Packers will try to keep them both.