Marshal Yanda (6-foot-3, 315 pounds, sixth season):The Pro Bowl right guard is arguably the Ravens' top offensive lineman. He has started every game for the last two seasons and anchors the right side of the line. He has the right guard spot nailed down heading into the season.
Howard Barbieri (6-5, 300, first season): The Rutgers product spent all of last year on the Houston Texans practice squad and was signed by the Ravens after the 2011 season. He is a versatile lineman that played every position along the line during his college career.
Justin Boren (6-2, 325, first season):Boren spent most of last season on the practice squad, but was pulled up on Jan. 3 in time for the playoffs, as he could have been targeted by another team. He was a gameday inactive for both postseason games. Boren can play right or left guard, and center.
Bobbie Williams (6-4, 345, 13th season):The veteran guard signed with the Ravens just before minicamp and was immediately thrown into the mix as a favorite at left guard. Williams is coming off an ankle injury that ended his 2011 season after nine games, but he says that he now feels healthy and ready to play.
Kelechi Osemele (6-5, 333, Iowa State): The second-round pick looked like the favorite at left guard before the signing of Williams. He played left tackle during his college career, but says he feels comfortable moving inside as well. The big lineman impressed during Organized Team Activities, and he could also end up playing right tackle, depending on how the rest of the line comes together.
Jack Cornell (6-6, 315, Illinois): The undrafted free agent started every game last year at Illinois. Cornell is a big-bodied lineman with the ability to play inside or also slide out to play tackle.
Gino Gradkowski (6-3, 300, Delaware):The fourth-round pick is making the leap from small-school competition to the NFL. He has played both guard spots and center during the offseason camps, and is largely considered the heir-apparent to veteran center Matt Birk. In the meantime, Gradkowski will compete for the left guard job.
Paul Madsen (6-4, 309, Colorado State):Claimed off waivers after initially signing with the Buffalo Bills, the undrafted rookie free agent played and started 11 games as a senior, garnering second-team, all-conference honors at Colorado State. He is also an option to play right tackle.
Antoine McClain (6-5, 329, Clemson): The undrafted free agent started 41 games during his four seasons with Clemson, and was the only player on the roster to start every game between 2009-2011.
The position battle for the left guard spot, which opened up this offseason when Ben Grubbs left in free agency, will likely be one of the most closely watched during training camp. Whoever ends up winning the job will have big shoes to fill, as Grubbs was a Pro Bowler and one of the Ravens' top players along the line.
The veteran Williams appears to have the edge in the competition, based on his experience. He has been a starter with the Cincinnati Bengals for the last eight seasons and gave the Ravens defensive linemen fits when he faced them.
"I'm not going to have as much of a headache anymore playing Cincinnati," Ravens defensive tackle Haloti Ngata said after Baltimore signed Williams.
While Williams looks like the favorite, the rookies aren't far behind. Osemele and Gradkowski took some of the reps with the first team during offseason workouts, and Head Coach John Harbaugh said that signing Williams was not because the team lacked confidence in the young players.
"We are just building an offensive line," Harbaugh said. "We'll have competition. Those young guys are going to be in there competing. The best guys are going to play."