Dolphins guard Dallas Thomas has plenty on the line in preseason opener

DAVIE, Fla. -- The Miami Dolphins have major questions at guard and one player in the center of it all is third-year offensive lineman Dallas Thomas.

Perhaps no player has more on the line Thursday than Miami's former third-round pick when the Dolphins travel to play the Chicago Bears in its preseason opener. Thomas is competing with rookie Jamil Douglas for a starting job at right guard and the position is up in the air.

Thomas and Miami's offensive line have been very inconsistent in training camp. One bad preseason performance by Thomas could push him down the depth chart.

"All games are important," Thomas said after practice Tuesday. "I just want to come out and work on my craft and see if everything I've been doing in the offseason has paid off."

The pressure is on Thomas this preseason in what may be his final chance to earn a full-time starting position with the Dolphins.

Douglas is showing promise in his first season and is splitting reps with Thomas with the first-team offense. Thomas also missed a couple days of practice last week with a shoulder injury, which provided more opportunities for Douglas.

"It's been close," coach Joe Philbin said of the guard competition. "I thought Jamil, for a rookie, the other night kind of [held] his own and out there. I thought he handled himself pretty well out there, I really did."

It's been three years for Thomas, and Miami's coaching staff hasn't figured him out. Thomas has played left guard, right guard and right tackle in games throughout his career. Thomas played mostly left guard in training camp. But on Tuesday, the Dolphins gave Thomas several reps at left tackle.

Miami likes Thomas' versatility. But in his third year, Thomas needs to be able to master as least one position to be a 16-game starter.

"I'm a guard, but the season is long," Thomas said. "So you never know what can happen. You always want to make sure you're prepared that if something does happen, I can get out there and hold it down."