Right guard Mike Pollak and right tackle Jeff Linkenbach prepare to block pre-snap. (Jonathan Daniel | Getty Images)

No unit on the football field lives and dies by the concept that a chain is only as strong as its weakest link more than the offensive line. When one player screws up an assignment along the line it can cause a total breakdown in protection.

Since Tarik Glenn retired following the 2006 Super Bowl Championship season, the Colts have played at least one offensive lineman out of position. Charlie Johnson, the Colts starting left tackle in 2009 and 2010, is not a true NFL-caliber left tackle and was not acquired to play that position. He had success at right tackle in the Super Bowl when Ryan Diem went down with an injury and has looked good at the guard positions, but left tackle is asking Johnson to play over his head.

Over the same period, right tackle Ryan Diem’s performance has steadily regressed. He is no longer capable of consistently protecting Peyton Manning against competent pass rushers and is too inconsistent run blocking. One could argue that some of his struggles may be from a revolving door at right guard, but even then it is clear from one-on-one match-ups on the outside that Diem is no longer able to get the job done.

Colts President Bill Polian attempted to prepare for the future in 2008 when he drafted three interior offensive linemen in one draft. The year prior he traded the 2008 first round pick to move up in the 2007 draft to select Tony Ugoh in the second round as the left tackle of the future. The problem is that Ugoh is no longer on the team and never lived up to expectations, second round pick Mike Pollak has failed to hold down a starting position at right guard in 2009 and 2010, sixth round pick Steve Justice was cut after his rookie season, and seventh round pick Jamey Richard has only had success at center on a limited basis.

Following 2009, the front office chose to cut long-time starting left guard Ryan Lilja. The stated rationale was that Lilja’s knee injury, which held him out of the entire 2008 season, posed lingering concerns. Unfortunately, Lilja played the entire year in Kansas City and would have easily started in Indianapolis if he was retained.

The team’s most consistent offensive linemen are an aging Jeff Saturday, whose replacement will need to be ready no later than 2012, and 2009 undrafted free agent acquisition Kyle DeVan, who has had success at left and right guard over the last two seasons.

These observations suggest that the Colts need numerous starting caliber offensive linemen from the 2011 NFL Draft, trades, or free agency. However, moving the current players on the roster around could very well go a long way in addressing much of the line’s concerns.

First, acquiring a legitimate left tackle via trade or the first round of the upcoming draft (trading up if necessary) will allow Charlie Johnson to move to a position more in line with his skills. Second, undrafted free agent Jeff Linkenbach proved two things in 2010. One, he is not suited to play guard. Two, he consistently had success at left and right tackle when he had opportunities to start on the outside — including a solid performance against Jets, in place of an injured Diem.

Adding a new left tackle, inserting Linkenbach at right tackle, moving Johnson in to right guard, and keeping Saturday and DeVan as starters should noticeably improve the offensive line.

There are other questions that may yet be answered in the off-season with players already on the roster. Jacques McClendon was added in the fourth round of the 2010 NFL Draft and has been developing at guard, center, and as an emergency tight end. If he develops as the Colts hope, he could compete for a starting spot on the interior of the line in 2011.

Jaimie Thomas is a bigger option at guard as well, and has spent the last two seasons developing after he was selected in the seventh round of the 2009 NFL Draft. Joe Reitz was added to the practice squad after he spent one week on the active roster — Week 1. He was acquired off of waivers from the Miami Dolphins who had acquired Reitz off of waivers from the Baltimore Ravens. Each of these teams entered the 2010 season with two of the top offensive lines in the NFL. If Reitz takes to the Colts system he should be competition for tackle depth — and possibly the starting right tackle spot.

The problem with this approach is that the Colts gamble to not aggressively address the offensive line after Bill Polian placed a lot of blame on the line for costing the Colts the 2009 Super Bowl has proven to be a mistake. Doing so for a second season in a row, hoping that developing players work out, could put the Colts right back in the same position seven months from now.

With so few positions of need leading up to the 2011 Draft, it makes more sense to pick three or four offensive linemen in the draft. Additionally, cutting Diem — or drastically lowering his salary — may work out to give Indianapolis enough room to make a trade or acquire a veteran free agent. No matter what direction the team chooses to take with Diem — who may deserve a shot to compete for a starting guard spot — an aggressive strategy to bolster the offensive line is the only acceptable strategy.

If the Colts enter the new season with a offensive line that consistently provides Peyton Manning with time to scan the field and can open holes for an efficient ground game, Indianapolis will be a scary opponent for any team. If Polian and company fail to address the problem for a second season, not only with the Colts offense suffer, but the line’s future will become an even bigger looming concern.