ESPNChicago examines potential unrestricted free agents at positions of need for the Bears.

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Most offensive guards are anonymous figures outside of their respective NFL cities, but don't underestimate the importance of the position. Teams that get solid play from their interior offensive line are able to be more creative and more successful in the run game, plus provide better pass protection up the middle, which allows the quarterback to step up in the pocket and deliver the football with more accuracy.

The Bears thought they were set at guard heading into the 2012 regular season, but a rash of injuries (Lance Louis, Chris Spencer), coupled with Chilo Rachal going AWOL, depleted the unit to the point where not only did former first-round pick Gabe Carimi have to bounce inside after he lost his starting right tackle, but the club was forced to play undrafted rookie free agent James Brown the final three games of the year.

The outlook for guard next year hinges on several factors, starting with Louis' recovery from the torn ACL he suffered in late November versus the Minnesota Vikings at Soldier Field. Louis is scheduled to be an unrestricted free agent, and before the injury, he was easily the best offensive lineman on the Bears' roster. Re-signing Louis, who continues to rehab at Halas Hall, would ease some of the concern inside, but not all of it, especially since it's unclear when exactly Louis will be able to get back on the field.

But that's just one of several questions the Bears face.

Brown has potential, but is it too early to pencil him in for a starting job with just three career starts? Is Carimi a guard or a tackle? Is Carimi even a starter moving forward? Does the team consider bringing back Spencer, also an unrestricted free agent, for the sake of depth? Is Edwin Williams still in the mix?

With so many unknowns, it's a safe bet the Bears target guard as an area to improve in the offseason. That help could come in the draft, where the 2013 class is said to be a strong one for offensive linemen. But if the Bears opt for experience inside, here are some of the projected unrestricted free agents who might be available starting on March 12.

Andy Levitre, Buffalo Bills: Levitre has started every game (64) at guard for the Bills since he entered the league in 2009 as a second-round pick out of Oregon State. He's young (26), durable and experienced. That's the hat trick for free agent offensive linemen.

Louis Vasquez, San Diego Chargers: With 54 career starts over the last four years, Vasquez is comparable to Levitre, although he is larger body-type standing 6-foot-5.

Brandon Moore, New York Jets: There were a couple of bright spots for the Jets this season, and Moore was one of them. The 10-year veteran right guard from the University of Illinois figures to be the most accomplished guard on the open market. Moore is 32-years old, but he's younger than Ruben Brown was when he helped anchor the offensive line that led the Bears to the Super Bowl in 2006.

Ramon Foster, Pittsburgh Steelers: A full-time starter for Pittsburgh the last two years, Foster is believed to be one of several Steelers' starting offensive linemen who could leave the team in the offseason.

Kevin Boothe, New York Giants: Boothe played early in his career with the Oakland Raiders, but spent much of his time in New York as a reserve until he made nine starts in 2011 when the Giants won their second Super Bowl. He then moved into a full-time starting role last season at left guard.

Matt Slauson, New York Jets: Slauson started all 16 games for the Jets at left guard the last three years, and also authored the much talked about cut block that ended Houston linebacker Brian Cushing's season in October.