It is usually said that a tackle problem cannot be solved in free agency, because rarely do franchise-caliber left tackles hit the open market. Once a team knows that they have a stalwart, anchor tackle on their line, they do everything they can to keep that guy on the roster.
Now for the other offensive line positions, this is not always the case.
The Bears need to add a couple linemen this year, possibly as many as three but most likely at least two. One tackle and a guard. I have seen some argue here in WCG that the team really just needs a guard and a center and that the team can continue to develop and get production from J'Marcus Webb, Jonathan Scott and Gabe Carimi.
Either way, though, the Bears need some offensive linemen, not just starters but also some quality depth. The team stands to lose Chris Spencer, Scott, Lance Louis and Chilo Rachal to expiring contracts.
Rachal is about as good as gone anyway since he left the team following his demotion and was placed on the Reserve/Non-Football Injury list. It is believed the team will try and re-sign Louis because he was the team's best offensive lineman before he got hurt and Scott stands to get a contract offer from the team as well due to his ability to add depth and for playing quality football in place of the struggling Carimi.
Now onto the free agents out there. Looking at the centers available it appears there are a few guys who are intriguing young players, but it will be interesting to see who actually reaches free agency.
Joe Berger, Vikings - Berger has not started a game since 2011 when he started seven and he has only been a full-time starter once in his 8-year career, in 2010 with the Dolphins when he started 14 games. Pro Football Focus graded him out with a neutral 0.0 for his 2012 efforts.
Brian de la Puente, Saints - Now here is a name not many will recognize. However, PFF has him rated as the best available FA center and gave him a +23.0 rating for the 2012 season. At age 27, de la Puente has only been a full-time starter since mid-2011 when Olin Kreutz surprisingly retired. The Saints may not let such a good, young lineman walk, but with his former coach Aaron Kromer here in Chicago, if he does hit the market, he could be swayed to sign here.
Jeff Faine, UFA - Faine began 2012 on the Cincinnati Bengals, who then cut him halfway through the season. Even at just age 31, Faine's best days may be behind him as he hasn't made it through 16 games since 2008 with the Bucs. He did start 15 games for the Bucs in 2011 though.
Todd McClure, Falcons - McClure is 35 but has been durable over his 14-year career. He missed three games in 2011 but before then he hadn't missed time since 2001. Pro Football Focus rates him at +6.7 for his 2012 season.
Fernando Velasco, Titans - Another name unfamiliar to some, Velasco just finished his first season as a full-time starter. PFF has him graded out at +13.0 for the year and he is only 27, so if the Titans were silly enough to let him walk, then the Bears should certainly take a look. The Titans' line was much-maligned this year but since PFF graded him out positively, it says a lot about his play.
The list of free agent centers goes on a bit with some other recognizable names, such as Dan Koppen, Phil Costa and Evan Dietrich-Smith. Here is the full list from Pro Football Focus I used for this post. Who is someone you'd like to see the Bears explore?