© Dale Zanine-USA TODAY Sports

There's a new deputy sheriff in North Texas. Only days after the 2020 season concluded in embarrassing fashion for the Dallas Cowboys, they pulled the trigger on a decision they'd been actively committed to doing for weeks -- firing defensive coordinator Mike Nolan and sending defensive line coach Jim Tomsula packing with him. The latter found himself joining Nolan on the hot seat for a variety of reasons, a primary one being the unwillingness to unleash defensive end Randy Gregory as starter, sources tell CBS Sports. And with the call to jettison Nolan after only one year, it'll be Dan Quinn serving as his replacement, the former Atlanta Falcons head coach agreeing to terms on a multi-year deal after an impressive in-person interview on Monday, those same sources confirmed.

It was Quinn's second Q&A with the Cowboys, his first having been virtual on NFL Super Wild-Card Weekend, along with Justin Simmons (secondary coach and defensive passing game coordinator of the Carolina Panthers) and Joe Whitt, Jr. (secondary coach of the Falcons). Quinn ended up overtaking the lead in-house candidate in George Edwards, the former Minnesota Vikings defensive coordinator who currently serves as senior defensive assistant for the Cowboys, with both Quinn and Edwards having been formally interviewed for the vacancy before Dallas made it's final decision to toss the keys to the former. And with that, the Cowboys get to have their defensive cake and eat it too, by way of retaining Edwards in his current role but in also landing their top external candidate to replace Nolan in a situation that combines the football IQ of both of their top candidates.

There are justifiable questions to the hiring of Quinn, given the lack of success the Falcons defense had during his time there, but a counterpoint is that he wasn't calling the plays, so it's unknown how much of that blame lies at his feet, outside of the obvious decision to see it floundering and ... well ... not take over play-calling duties. 

So, what's next in Dallas, with Quinn now secured? 

Well, lots, so let's dive right into the science of what's on tap defensively for Dallas this offseason. 

Treating the possible 'staff infection'

Nolan and Tomsula weren't the only defensive coaches desperately looking for ice to cool their rear ends to close out the 2020 season. Sources told CBS Sports in mid-December there were/are also "passionate" discussions regarding the future of linebackers coach Scott McCurley and secondary coaches Maurice Linguist and Al Harris. As it stands, there doesn't appear to be any heat beneath the rump of stalwart assistant defensive line coach Leon Lett, but ultimately it'll be up to Quinn to decide who the position coaches are. Considering there were also fractures and consistently poor play in the secondary in 2020, the breakout rookie year by second-round pick Trevon Diggs and coming out of party of safety Donovan Wilson notwithstanding, it stands to reason the fuming finger of owner Jerry Jones would extend beyond Nolan to his subordinates, but Jones stopped short of cleaning house -- the goal being to allow Quinn to make the remainder of those calls.

And very soon, he will.

This is where things could get even more interesting than they already are in Dallas because, as noted, the Cowboys interviewed Whitt for the DC vacancy and Whitt was Quinn's defensive backs coach for the Falcons in 2020. That said, it's likely the two will discuss the possibility of reuniting in Dallas, and while it's to-be-determined if Whitt makes a lateral move to a team who passed on him for the bigger role, it's far from impossible, especially considering his ties to McCarthy from their time spent together with the Packers. Another option would be to give Kris Richard a call, the hope being they can smooth ruffled feathers by admitting they made a mistake in letting him go during the 2020 regime change. Richard served as the Cowboys passing game coordinator and defensive playcaller in 2019 but, before that, he was a protégé of Quinn's in Seattle -- ultimately taking the mantle as leader of the Legion of Boom when Quinn took the role as head coach for the Falcons in 2015.

The two not only know each other exceeding well, but they coach the same scheme (considering Quinn helped impart his onto Richard, who then added his own refinements), which would make for a much more impactful reunion that potentially that of Quinn and Whitt. This isn't to say Whitt would be a bad call, but simply to reinforce the difference in the level of success and time spent together between all in the past. Richard is currently in discussions with the Las Vegas Raiders (read: Rod Marinelli), but it's worth the Cowboys swallowing their pride to ask him for a do-over.

And if Richard is open to it, he'll be a name to watch as Quinn works to iron out his staff. 

What you got on my 40?

It wasn't that the idea of establishing a hybrid defense was bad, it was Nolan's failure to read the room that forced it into catastrophic collapse, as he attempted to shoehorn a massive amount of information into the minds of players without the benefit of minicamp for a traditional install or preseason to test drive the implementation thereof. An easy out for Nolan would've been to pause his install and to then integrate it in phases -- ideally four -- over the course of season quadrants, but his approach instead alienated the locker room and created fractures that became public, both verbally and by a dismal lack of effort on consistent occasion. With Quinn, the Cowboys won't have such an issue, because he's not looking to install a super-creative defensive scheme that requires a ton of adjustment from some players who are already Pro Bowlers and All-Pros at what they do.

He's looking to revert back to what got them where they are now.

It's the return of the 40 front in Dallas, i.e., the 4-3 setup, and that sound you hear is probably DeMarcus Lawrence and others popping champagne bottles in celebration. For while Lawrence had an impressive year despite Nolan, many others saw theirs tank, particularly linebackers Jaylon Smith and Leighton Vander Esch -- Smith now needing to be taken to the shop for repairs (plural).

Expect Gregory to be unleashed as full-time starter opposite Lawrence in 2021, and both will play nearly all of their snaps with their hand in the dirt as a 5-tech, allowing them to get after the opposing quarterback in the way they best know how. You can look to what Quinn did in his time as Super Bowl-winning defensive coordinator with the Seattle Seahawks for insight in what's to come for the Cowboys, which will probably include the deployment of the LEO front -- three down, one up -- but that will not be the base nor the norm. This means the Cowboys won't have to overhaul how they search for personnel to fit a new scheme, but can instead focus on revaluing key positions they've been consistently ignoring for years, which is a much easier fix -- if McCarthy and Quinn are allowed to do so.

Slow money doesn't mean no money

Speaking of revaluing positions, hello NFL free agency.

McCarthy's influence was immediately felt in his first go at free agency in Dallas, when the club signed Gerald McCoy, Dontari Poe and HaHa Clinton-Dix to the team. Granted, things didn't go nearly as planned for Poe and Dix -- McCoy suffering a season-ending injury before the season began, Dix not surviving final roster cuts and Poe later released for cap space following poor play on a weekly basis -- but it's the shift in priority that's the key takeaway. Usually, the Cowboys wildly ignore the importance of upgrading the defensive interior (especially nose tackle) and opt for bargain shopping there and at safety. That was different in 2020, and while they mostly whiffed, it's good news to see they've already began the process of applying more value to long-ignored positions on defense. 

And with this offseason expected to be focused primarily on throwing the kitchen sink at rebuilding a defense that was statistically the worst in NFL history, there's a lot for Quinn to be excited about. 

What he might have to contend with, however, is a salary cap issue that may or may not be made better by a long-term deal with two-time Pro Bowl quarterback Dak Prescott -- or a $37.7 million franchise tag in the absence of one -- in a situation that could cash-strap the defensive rebuild in free agency. There will be options though, and of course you'll hear it into the depths of eternity until/unless it finally happens or he retires: Earl Thomas could be one of them.

Thomas was forced out of football in 2020 due to a variety of toxic events that mushroomed into him being voted out of the Baltimore Ravens organization by his own teammates, and even players of the exceptionally bad Houston Texans voted against signing him after then head coach Bill O'Brien was planning to do so. As for as the Cowboys went, a team that once attempted to send a premium draft pick to the Seahawks in exchange for him opted to turn their back and, as CBS Sports consistently reported, it was because McCarthy wanted nothing to do with the baggage that comes with an aging Thomas. That is still currently the situation for Thomas in Dallas, sources again noted this January, but Quinn is his lighthouse in the storm. 

As a member of the Legion of Boom, Quinn knows how to manage Thomas, and that's a potential in for him in Dallas. But if Thomas' time with Quinn wasn't so favorable behind the scenes, don't expect Quinn to pound the table and risk his shiny new position when McCarthy is already iced over about the topic.

Wilson has earned his role as starter and even played well when tasked with taking reps at free safety, the hard-hitting ballhawk giving Dallas flexibility in which safety position they address first in 2021, but Quinn loves elite safety play so expect him to do his best to ensure the Cowboys are finally all set at both the free and strong roles. Keep an eye on players like Keanu Neal (safety) and Damontae Kazee as possible rollovers to Dallas from Quinn's time in Atlanta, Kazee being a viable option to help resolve much-needed depth issues at both safety and corner (considering he's also played the latter) while Neal's youth and talent would be an exceptional complement to that of Wilson, if Neal can remain healthy -- as he mostly did in 2020.

From there, addressing the defensive interior will be paramount, and he and McCarthy are on the same page there, although they'll have to get creative with their spending. 

Proofread the final ... draft

Here's where most of the impact will be made for the Cowboys defense going forward.

As disappointed as Jones was/is at how the season went defensively, he's a kid in a candy store at the moment, knowing his offense is all set to again be healthy and prolific for 2021 -- allowing him to go full bore at revamping his defense in the draft. With the 10th-overall pick in April, and a projected 10 picks overall, the Cowboys are locked and loaded to give Quinn and McCarthy whatever they need on the defensive side of the ball. This is where the success or failure of Quinn will be decided, so whiffing is not an option, nor would be pretending they can again pull a BPA (Best Player Available) trigger in the first round if said pick involves making an already gleaming offensive unit that much more shiny. 

That's a temptation to resist at all costs, and it would be unnecessary greed that could be their downfall next season, after having already rightfully secured CeeDee Lamb in the last draft. No, instead look to the budding success of a pick like Neville Gallimore and go from there. 

The current roster, generally speaking, isn't going to cut it for Quinn, and especially considering several starters are set to hit unrestricted free agency and likely won't return, not that some of them need to anyway. With the team set for a good amount of what can be viewed as positive turnover -- that quotient being contingent upon who replaces the outgoing free agents -- now is a perfect time to draft defense, and then more defense, and then some more defense after that. Quinn's return to the 40 front (4-3) will require a dominant interior to match his dominant edge rushers in Lawrence and Gregory (and possibly Aldon Smith along with ... ahem ... Bradlee Anae?), and veteran retreads in free agency are probably not the answer.

After all, Antwaun Woods has proven himself a starter in the league and Neville Gallimore is on the upswing heading into Year 2, setting the stage for a competition with returning former second-round pick Trysten Hill. This is all to say the Cowboys might be set atop the depth chart on the defensive interior, and that would allow them to save cap space by foregoing on an aging veteran and instead using a draft pick or two to help in solidifying their run defense. Quinn and McCarthy want beef up front, but also love elite safety play on the back end, so these will be his aims going into the offseason; with both of these items ideally helping the linebacker corps play improved football by virtue of shrinking their field of play and the number of decisions they're forced to make on a weekly basis. 

All the Cowboys have to do is agree, and then get to work scouting to make sure Quinn isn't one-and-done like Nolan was.