Based on the long held belief that football games are won or lost in the trenches, the success or failure of the Winnipeg Blue Bombers in 2012 could very well be decided by how they fill a pair of gaping holes on their offensive line.  

Or to quote a member of the Bomber bass, "Our season revolves around how good our offensive line is."

All-Canadian Guard Brendon Labatte left Winnipeg to sign as a free agent with Saskatchewan, and veteran Center Obby Khan retired after a 2011 season in which he spent a lot of time on the sidelines.  

There are no shortage of candidates to replace LaBatte and Khan, but after 10 days of training camp, the questions about who will take their places have yet to be answered.

Chris Kowalzcuk was, and perhaps still is, the top contender to play the center position.  

The challenge for Kowalczuk is that he has virtually no professional experience on his resume even though he is 27 years old.   

Graduating from the University of Toronto in 2009, Kowalczuk spent two games on Hamilton's practice roster toward the end of the same season.  

He was signed by Winnipeg as a free agent in 2010 and has yet to play in a regular season game, spending all of his time on the Bombers practice roster and injured reserve list.  On top of that, Kowalczuk played guard and tackle in college, so learning the intricacies of playing center requires a learning curve.  

Challenging Kowalczuk for the center spot is gigantic Justin Sorenson.  Sorenson was a highly rated prospect when the B.C. lions made him their first round draft pick, 5th overall, out of South Carolina in 2008.   

He dressed for all 18 Lions games in 2009 and 2010, starting a handful of them.   

But Midway through the 2011 season, the Lions gave up on Sorenson, handing him his outright release.  He joined Winnipeg on Aug. 30 and spent the rest of the year on the practice roster. If size matters, Sorenson is money at a towering 6-foot, 7, 330 pounds.

While Sorenson and Kowalczuk fight it out for the center spot, the left guard position is Chris Greaves' to lose.  

Greaves was a defensive lineman at the University of Western Ontario, but the Bombers drafted him in the sixth round in 2010 with the intention of converting him to the offensive line.  They hope the conversion is complete.  

Greaves dressed for five games in 2010, starting one. In 2011, he was in uniform as Winnipeg's sixth offensive lineman for every game, starting the final three at left guard. Greaves still has to be considered a "project" but the Bombers are counting on the project being concluded in time for their regular season opener.  

Veteran Canadian Steve Morley is secure at the right guard position (and he could be moved to center as a last resort), while Americans Andre Douglas and Glenn January are penciled in as the starting tackles, although both are currently idled with what are considered minor injuries.   

So, just over two weeks before beginning the 18-game CFL regular season grind, the Blue bombers couldn't be blamed for being just a little bit anxious about one critical component of their team, the makeup of their offensive line.