ESPNChicago examines unrestricted free agents by position that might interest the Bears.

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Roberto Garza enters the final season of a two-year extension signed in November of 2011. But he'll be 34 in March, leaving the Chicago Bears to ponder the possibility of life after the center, which played well enough in 2012 to be considered one of the most underrated performers on the club's wildly inconsistent offensive line.

The new coaching staff plans to clean up issues up front through a combination of tightening up technique and new additions. Garza certainly gives the Bears a strong foundation on which to build in 2013, but the team needs to acquire his eventual successor.

Based on the current free agent market, the best way to do that will be through the draft or by sifting through the current roster, which includes candidates such as Edwin Williams, Lance Louis and pending free agent Chris Spencer, who played center for most of his career before switching to guard with the Bears.

Garza graded negatively in five of the 16 games, and according to Pro Football Focus, gave up five sacks, one quarterback hit, and eight pressures in 1,071 snaps. Not exactly an all-Pro performance, but the Bears can win with that if they can get Garza's level of consistency from all five players on the offensive line.

The Bears list Williams as the backup to Garza on their unofficial depth chart. Williams played six games in 2012, and started two at left guard. Spencer, who at this point appears to be on the way out, is a former first-round pick who started in 60 games at center over a six-year span in Seattle before joining the Bears and moving over to guard.

Louis, meanwhile, possesses the skills to play center in a pinch. But Louis' niche is at right guard, where he was arguably the club's best offensive lineman through the first 11 games, before a knee injury knocked him out for the final five outings.

A free agent likely to be a one of the club's priorities this offseason, Louis appears to be the long-term starter at right guard if he can return without a hitch from knee surgery.

So at this point, Garza is definitely the most logical option to anchor the rebuilding effort in 2013 for the Bears, who might need to draft his eventual successor sometime this spring because three of the top potential fits for the club are restricted free agents while for more are 30 or older.

Here's the top five listed alphabetically:

Phil Costa, Dallas Cowboys: He's somewhat of an unknown because he became the starter due to injuries, but only played approximately a game and a half before going on the injured reserve. A restricted free agent, Costa isn't a dominating player, but he's young (rising third-year veteran), smart and versatile. It's an unlikely scenario, but Cowboys may not be inclined to tender him, which means there's a chance -- albeit small -- Costa could come at somewhat of a bargain and be groomed to eventually start.

Brian De La Puente, New Orleans Saints: Played in a whopping 1,134 snaps in 2012, which ranked as the fourth-most in the NFL. Yet he allowed just two sacks, in addition to four quarterback hits and 10 pressures for New Orleans' pass-happy offense, according to Pro Football Focus. At 27, De La Puente is entering the prime of his career. But he's a restricted free agent. So landing him wouldn't be easy for the Bears.

Dan Koppen, Denver Broncos: A longtime starter for the New England Patriots, Koppen joined the Broncos last season and didn't log his first start until Oct. 7. In 14 games (counting the playoffs), Koppen gave up only one sack. A two-time Super Bowl winner, Koppen has worked with Tom Brady and Peyton Manning. But he also turns 34 in September.

Todd McClure, Atlanta Falcons: He's got familiarity with general manager Phil Emery, but McClure is also 35 years old, and we all know this is a young man's game. Besides that, McClure doesn't represent a real upgrade at the position. He allowed five sacks in 2012, along with five quarterback hits and 14 hurries.

Fernando Velasco, Tennessee Titans: Another restricted free agent, Velasco will be 28 this month. Velasco put together a shaky performance in Week 2 at San Diego, but rebounded to play solid ball the rest of the season. Velasco didn't allow a sack all season, but he did surrender nine pressures.