FRISCO, Texas -- They would walk side by side together from the makeshift locker room and murmurs would run through the crowd of Dallas Cowboys fans. This does not usually happen when offensive linemen make their way out to most other NFL training camp practices.

But most offensive lines are not comprised of three first-round picks who are among the highest paid at their positions and a fourth who went undrafted but should have been drafted if not for being linked to an investigation into the murder of his pregnant former girlfriend prior to the 2015 NFL draft.

Tyron Smith, Zack Martin, Travis Frederick and La'el Collins were the ultimate security blanket and a big reason why quarterback Dak Prescott, running back Ezekiel Elliott and wide receiver Amari Cooper had success in the past.

Now, in 2020 as we enter Week 9? Only Martin remains active.

The rest of the Cowboys' current offensive line could walk almost unrecognized if they were allowed to go out in public as a group.

In the search of things that have gone wrong for the Cowboys, start with Prescott's injury and then mix in all of the defensive woes from a scheme change. But don't wait too long to get into the offensive line.

The O-line woes began when Frederick retired in March, and it continued when Collins was unable to practice and then he had a hip injury that required surgery and ended his season before it began.

In the second week of regular-season practice, Smith suffered a stinger in practice. He missed two games, returned for one and then had season-ending neck surgery.

Martin, one of the best guard's in the NFL and a team leader, effectively missed two games because of a concussion suffered seven snaps into the Oct. 19 loss to the Arizona Cardinals.

The Cowboys have employed nine different offensive line groupings in eight games, including five different starting configurations. They have not had the same five players start more than two straight games. In last week's loss to the Philadelphia Eagles, Martin returned to right guard with Cameron Fleming and Terence Steele lining up at tackle with Connor Williams at left guard and rookie Tyler Biadasz at center.

This week, the Cowboys face the unbeaten Pittsburgh Steelers (7-0) at AT&T Stadium (4:25 p.m. ET, CBS). Pittsburgh has the No. 5 ranked defense in terms of yards per game and ranks No. 6 in points per game. The Steelers also lead the league in sacks. T.J. Watt (6.5), Stephon Tuitt (6) and Bud Dupree (6) have combined for 18.5 sacks; the Cowboys have 17 as a team.

"I've always felt the biggest challenge of an offensive line was consecutive starts," Cowboys coach Mike McCarthy said. "When you have five offensive lineman that play together week in and week out, that doesn't always equate to a very efficient offensive line, but if you look at the statistics of consecutive starts by an offensive line group, the winning percentage is extremely high. The stabilization of your offensive and defensive line is a key component to being successful in this league."

When McCarthy won the Super Bowl in 2010 with the Green Bay Packers, left tackle Chad Clifton, left guard Daryn Colledge, center Scott Wells and right guard Josh Sitton started every game. Right tackle Bryan Bulaga started 12 games.

In 2017, his last full season in Green Bay, the Packers used 11 different offensive line combinations.

In 2019, the Cowboys had five different starting offensive lines. From 2016 to 2018, they had four. In 2014 and 2015, they had three.

Two weeks ago, Williams was the Cowboys' most experienced starter on the line. The 2018 second-round pick had 28 career starts. Erving was making his first start with the Cowboys. Biadasz was on his third. Connor McGovern, a third-round pick in 2019, was making his first. Steele, who was undrafted in 2020, was making his seventh.

"Overnight you can't teach experience and you can't teach reps, but you can teach hard work and effort, and I think that's what we're instilling," Williams said. "At the end of the day, that's what we're going to hold our hat on and that's what's going to win."

Imagine being Joe Philbin. When McCarthy hired him as the Cowboys' offensive line coach, he thought he was inheriting one of the best units in football. By the time he got to his first game, he was without two-fifths of the experience that he was projected to have in January.

McCarthy, who worked with Philbin in Green Bay, called him "an outstanding teacher."

"Joe's teaching skills, his consistency of his demands of the players, he has a great dry sense of humor, his motivation is constant," McCarthy said. "So that's a good group. Frankly, we need to continue to grow. We have some young tackles that have been added to our O-line group and young centers who are getting better. It's a group that has a lot of growth potential in front of it, and Joe is the perfect man for the job."

Growth is difficult when there is a new combination of line mates nearly every week.

"Obviously we talk all the time, offensive line, getting that continuity down," Martin said. "Unfortunately we haven't had that at times this season. Again, there's no secret to this thing. It's about going back out to work, getting the reps with the guys that are going to be in there and trying to build that on the go."