Can quarterback Dak Prescott bounce back from a sophomore slump? Can star running back Ezekiel Elliott recover from a second season that was derailed by a six-game suspension? Can they survive without Jason Witten and Dez Bryant? What's up with Terrance Williams? Is the offensive line not as dominant as it used to be? And if that's the case, will Prescott, Elliott, Williams and the rest of the skill-position players continue to float back to earth?
The vast majority of the focus on the Dallas Cowboys surrounds an offense that shocked the league in 2016, struggled quite frequently in 2017 and has undergone some potentially traumatic changes thus far in 2018.
That might make it easy to overlook the fact the Dallas defense is becoming special, which is also understandable because nearly a decade has passed since anyone has been able to say that with a straight face.
In terms of points allowed, the Cowboys have ranked better than 13th just once (2016) in the last eight seasons. Ditto in terms of total defense (2017) and takeaways (2014). When it comes to Defense-adjusted Value Over Average (DVOA), Football Outsiders has ranked the Dallas D in the bottom half of the league in each of the last six years, and it hasn't cracked the top 15 since 2009.
But it's somewhat encouraging that the Cowboys surrendered just 5.1 yards per play (compared to a league average of 5.3) and 318.1 yards per game (compared to a league average of 334.1) in 2017. Only a dozen teams gave up fewer points per outing, and for the second consecutive year, they at least ranked in the middle of the pack in terms of takeaways.
Was that an indication the Cowboys defense is about to become a major asset for the first time since it allowed an NFC-low 15.6 points per game under the tutelage of Wade Phillips back in 2009?
Among the 14 players expected to start or play key roles, only one (linebacker Sean Lee) is older than 28. All but three (Lee, 28-year-old defensive end Tyrone Crawford and 27-year-old safety Jeff Heath) are 26 or younger.
The average age of their defensive core is 24. They have a first-round pick on the defensive line (Taco Charlton), a first-rounder in the linebacker corps (Leighton Vander Esch) and another one in the secondary (Byron Jones), plus seven other Day 2 picks (second-rounders Demarcus Lawrence, Lee, Jaylon Smith and Chidobe Awuzie and third-rounders Crawford, Maliek Collins and Jourdan Lewis).
They're young, deep and talented, but they've also proved quite a bit already.
Lawrence is coming off a Pro Bowl season in which he was the only player in the NFC to record 12-plus sacks while forcing four or more fumbles. Lee, an All-Pro in 2016, is often dominant when healthy. Awuzie and Lewis, who were selected a couple of hours apart on Day 2 of last year's draft, both graded out among the top 50 corners in the league at Pro Football Focus last season.
Per PFF, Awuzie gave up just 7.0 yards per reception and 0.69 yards per coverage snap—both the lowest marks recorded by a rookie corner since that outlet started tracking such stats in 2006. The sample is small because he was limited to just 309 snaps while battling a hamstring injury, but it's scary to think how much more effective he can be with a healthy body and a full offseason under his belt.
Meanwhile, Lewis was one of just 10 players in football to record 10-plus passes defensed despite starting fewer than 10 games in 2017.
That duo has the ability to become one of the best cornerback tandems in football very soon, and it helps that they're complemented well by three defensive backs—Jones, Xavier Woods and Anthony Brown—who were all magnificent when covering the slot last season. That secondary—which is now run by former Seattle Seahawks defensive coordinator Kris Richard—has "Legion of Boom" potential.
As PFF's Steve Palazzolo wrote earlier this month, Cowboys defensive coordinator Rod Marinelli "has shown that he's capable of adjusting his scheme to his personnel, but Dallas has had an influx of youth in the back seven that is capable of playing man or zone while showing the skill sets to handle any style of receiver or tight end."
Based on their ages, pedigrees and trajectories, those units should only get better, making life easier on Lawrence, Crawford, Charlton, Collins and David Irving up front. One hand washes the other, and this Dallas defense has become so deep and versatile at all three levels that it's as easy to envision the front seven saving the secondary as it is to envision the back seven saving the defensive front.
It's also encouraging that there's plenty of continuity among that group. All 14 of the key defensive players that make up the core of this defense—Lawrence, Crawford, Collins, Irving, Charlton, Smith, Lee, Vander Esch, Awuzie, Lewis, Woods, Heath, Jones and Brown—have never played for another NFL team. Twelve of them were drafted by Jerry Jones and Co.
This isn't a dream team, and there won't be questions about how veterans coming from other teams will jell. The Los Angeles Rams might have bigger names on defense, but there's no telling how Ndamukong Suh will work with Aaron Donald or how Marcus Peters and Aqib Talib will mesh in the secondary.
These Cowboys are deeply familiar with each other and only each other. The only new arrivals are the rookie Vander Esch and 20-something-year-old free-agent pickups Joe Thomas and Kony Ealy, who aren't expected to play major roles as reserve front-seven defenders.
That indicates the Cowboys know they have something special and aren't trying to fix what ain't broke. This unit gave up just 12.4 points per game during the final five weeks of the 2017 regular season, which was the second-lowest mark in football over that stretch. It also ranked second in terms of yards allowed and tied for fifth with nine takeaways during that span. Those numbers might have been inflated a tad as a result of a soft schedule that included a Week 17 gimme against the resting Philadelphia Eagles, but they still indicate major progress.
All of the seeds have been planted, and now the Cowboys are letting them grow. If all goes according to plan, that defense will hit its stride together and become an elite group in 2018.
And if that happens, all of the pressure will be on the offense this time around.
Brad Gagnon has covered the NFL for Bleacher Report since 2012.