When Bill Parcells took over as the head coach of the Dallas Cowboys in 2003, he brought the idea of progress stoppers with him. Aptly named, progress stoppers prevent others from developing into even better players at a given position.

Often, these are typically older, veteran players who may have once been stars or solid contributors but are now on the tail-ends of their careers. But, even younger players can be progress stoppers if better replacements exist lower on the depth chart. The current Cowboys front office philosophy seems to ignore the second possibility, however.

Despite the worries about pass rush before the season, the Cowboysfront office rebuffed the idea of getting outside veteran help. Instead they argued their young players just needed time to develop and a veteran would only hinder that progress.

From the chart above, its pretty clear that Tyrone Crawford and Demarcus Lawrence are progress stoppers.Even though he had over 600 snaps, Crawford only managed 4.5 sacks on the year. Still, since he was third in sacks on the defensive line, it might seem odd to claim that Crawford is a problem.

The issue is revealed when you look at their average salaries. Paying Crawford for one year could cover the combined salaries of Jack Crawford, David Irving, Demarcus Lawrence, Maliek Collins, Terrell McClain and Benson Mayowa.

Sep 25, 2016; Arlington, TX, USA; Dallas Cowboys defensive tackle Tyrone Crawford prior to the game against the Chicago Bears at AT&T Stadium. Mandatory Credit: Matthew Emmons-USA TODAY Sports

Furthermore, he doesnt really have a defined role. Collins proved himself at the 3-technique and has earned the right to enter the 2017 season as the starter. David Irving showed tremendous potential in limited snaps at left defensive end and nearly had as many sacks as Crawford on 139 less snaps. Playing Crawford ahead of either of the two only prevents the younger players from developing further.

Lawrence is problematic in a different way. Hes not particularly expensive and is still very young, only 24. However, the defensive end dissapointed last season. He managed only one sack on the year and was fairly ineffective. To make matters worse, 2017 will be the second season that he starts on the mend after back surgery.

Giving up completely on Lawrence doesnt make sense, but the team has to stop treating him as someone they can rely on. Until he can prove his back issues wont affect his performance as they did in 2016, the Cowboys should treat Lawrence as a rotational player at best. Continuing to pencil him in as a starting end each year only prevents players, like Mayowa and Irving, from getting more snaps to continue developing.

Oct 9, 2016; Arlington, TX, USA; Dallas Cowboys defensive end Demarcus Lawrence (90) prior to the game against Cincinnati Bengals at AT&T Stadium. Mandatory Credit: Matthew Emmons-USA TODAY Sports

Demarcus Lawrence is in the last year of his rookie deal and Crawford will cost over $10 million against the cap if cut this year. Thus, its unlikely either leave Dallas in 2017.However, to get this defensive line moving forward, the pair need to be relegated to rotational duties. If the two want their jobs back theyll have to show they deserve them.

The rest is here:

The surprising progress stoppers on the Dallas Cowboys defensive line - Cowboys Wire