IRVING, Texas – There was a time when QB Tony Romo knew for the most part that Flozell Adams or Doug Free would be his left tackle, Marc Colombo his right tackle, Kyle Kosier his left guard, Andre Gurode his center and Leonard Davis his right guard.

But that was so 2007-10, when Cory Procter (11 starts in 2008) was the only other offensive lineman to crack the lineup on a consistent basis, and that came about because of a Kosier injury.

Now Romo enters a season not knowing who will be where or for how long.

Tony Romo will again take the first snap of a season behind different starters on the offensive line. Ronald Martinez/Getty Images

For the fourth straight year, the Dallas Cowboys will open the season with a different starting five when they host the New York Giants at AT&T Stadium. Four days before kickoff, the Cowboys are still kicking around O-line options.

The only locks are Tyron Smith at left tackle and Travis Frederick at center. It sure looks like Ronald Leary will start at left guard, with Mackenzy Bernadeau at right guard and Free at right tackle. But it is possible Free could be the right guard and Jermey Parnell the right tackle.

In Week 2 you could see Brian Waters at right or left guard against Kansas City.

“I think you’ve just got to trust your offensive line, and then you adjust obviously as the game moves on,” Romo said. “But if you go into it thinking some guy’s not going to do his job, then that doesn’t help anybody and you find yourself trying to do too much. I don’t think you can do it that way.”

From 1992 to '95, Troy Aikman had only four new faces on the starting line, with Mark Tuinei, Nate Newton, Mark Stepnoski and Erik Williams the constants in three of those four years. The right guard changed every year, from John Gesek to Kevin Gogan to Derrek Kennard to Larry Allen. Ray Donaldson was the center in 1995.

For most of his career, Roger Staubach knew he would have Ralph Neely, John Niland, John Fitzgerald, Blaine Nye and Rayfield Wright protecting him, with mixes of Dave Manders, Herb Scott, Tom Rafferty and Pat Donovan over the years.