Coming into the 2011 season, T.J. Lang had a lot to prove. He'd shown some promise at guard during his first two seasons, but faced only mild competition from Derek Sherrod during the preseason before securing the starting left guard job. And he did a fantastic job in his first season as a starter. He'll be a free agent next March, but the Packers are almost certain to extend his contract before then. With the departures of Chad Clifton, Daryn Colledge, and Scott Wells over the past two years, there's room for him under the salary cap. Bryan Bulaga won't be a free agent until after the 2014 season, so they can afford to take care of Lang now.
Ray Dominguez has played at both guard and tackle, but he's currently listed as a guard. He spent most of the last season on the practice squad, and he'll be eligible for it again in 2012. He was as good as any reserve lineman who played last preseason, but he wasn't great, and the pool of undrafted rookie free agents (Barclay, Brooks, and Cook) could challenge him with a strong preseason of their own.
Overall competition level: medium. While the starters are set, the backup position is wide open. Not only are four players battling for what could be only one spot on the practice squad, they also have to worry about spill over competition from the tackle position (that'll be a future post). This will be a position I'll be watching this preseason because I really want one of these players to step-up and establish himself as the clear backup guard.