FRISCO, Texas -- Over and over the past few seasons, the Dallas Cowboys’ offensive linemen kept hinting at Doug Free’s importance. They didn’t want to delay expressing their gratitude to the veteran right tackle.

Free opted to retire in the offseason, calling it a career after 10 seasons. Perhaps fitting to his low-key career, he had a retirement party away from the bright lights of a Dallas steakhouse for a seafood restaurant not far from his suburban home.

All of his offensive line teammates showed up. So did Jason Witten. So did Tony Romo.

If they didn’t want to delay their gratitude when he played, they certainly didn’t want to delay it when Free opted to walk away.

Zack Martin, Travis Frederick and the rest of the Cowboys' offensive line help make Ezekiel Elliott better -- and vice versa. Tim Heitman-USA TODAY Sports

“I just think he was the most consistent pro,” All-Pro guard Zack Martin said. “I think people don’t realize how much we’re going to miss him on and off the field. He was just the same guy every day. He came in, didn’t say much, went to work and then did it every day. He did it for 10 years.”

What Free learned came from Marc Colombo and Andre Gurode. They learned it from Flozell Adams and Larry Allen. They learned it from Nate Newton and Erik Williams.

Now the generational teachings are left to Tyron Smith, Travis Frederick and Martin. It’s up to them to teach it to La’el Collins, Jonathan Cooper, Joe Looney, Chaz Green, Byron Bell, Emmett Cleary and whoever else will call the Cowboys’ offensive line room home this season.

“It’s amazing when you look around in there and this is the first offseason [with the Cowboys] for more than half the guys in the room,” Frederick said. “We’re going over drills that we’ve done a lot, but really kind of moving back to the basics, trying to get everybody back on the same page where before there was a little more veteran guys who’d been around and you had one or two guys that kind of had to figure it out. Now it’s the majority of the guys that are just seeing their first offseason with this.”

There is no secret sauce to the formula that has made the Cowboys’ offensive line either the best or among the best the last few seasons. Talent helps. Smith, Frederick and Martin were first-round picks. Last year they were named first-team All-Pros. The running back, Ezekiel Elliott, matters, as Jason Garrett likes to say. The scheme helps too.

But the work matters most. Free made sure the group was about work more than words. They pride themselves on being the hardest-working group on the team and the coaches believe that trickles down to everybody else.

“Everybody has a different role in our room,” Frederick said. “I wouldn’t say there’s one clear leader because of the way Tyron works, the way that Zack plays on the field. Guys have a lot of visual aids and visual leadership.”

It’s up to the new guys to fall in line.

“The more time you spend playing, the more kind of credibility you have,” Martin said.

Free wasn’t the only loss on the line. Ronald Leary, who replaced an injured Collins at left guard last season, signed a big deal as a free agent with the Denver Broncos. The Cowboys are looking at a number of options in how to fill out their line, but so far they have had Collins at right tackle and Jonathan Cooper, a former first-round pick, at left guard.

“You need to be used to playing together,” Martin said. “We’ve been lucky the last three years having the same guys. It’s unfortunate Doug retired and Ron left, but we’ve got a ton of guys who can play and it’s going to be fun to have that competition and see what happens going into training camp.”

The Cowboys still are considered the front-runners to have the best line in football, mostly because of Smith, Frederick and Martin -- as well as Elliott. The quicker they can settle the right tackle and left guard spots the better for the continuity that is a big part of line play. The quicker they settle that, the quicker they can do what Free did every day: go to work.

“We’re trying to get everybody on the same page so we can get to clicking, and Doug’s missed in that he was the guy that kind of pulled everybody together and kind of showed us the ropes,” Frederick said. “Now Zack and Tyron and myself, we have to do our best to take what he taught us and help pass that on to the younger guys.”