Continuity is critical at any level of football, but especially in the NFL.
Finding continuity across offensive and defensive lines has the potential to make or break a team's success, because intricate blocking assignments, stunts and blitzes all depend on players' knowledge of the game and feel for one another.
After finishing 13-3 in 2015, the Arizona Cardinals were able to maintain a strong sense of continuity across their defensive front, as starting defensive end Calais Campbell, nose tackle Rodney Gunter and defensive tackle Frostee Rucker all planned on returning the following season.
With outside linebacker Markus Golden set to return and trade acquisition Chandler Jones expected to make an immediate impact, the Cardinals entered the 2016 season excited about the potential of the team's defensive front.
However, even though Gunter and Rucker both held down starting spots in 2015, the Cardinals were actually willing to forego the sense of continuity they had the potential to enjoy in hopes that competition would make the team even stronger.
With nose tackle Corey Peters returning after an injury wiped out his 2015 season and third-year undrafted free agent Josh Mauro continuing to demonstrate improvement, Arizona had a full stable of defensive linemen eager to compete for starting opportunities.
By the end of training camp, Gunter and Rucker were no longer assured of the starting roles they held the previous season, as the Cardinals felt they were deeper along the defensive line than they had been at any point during head coach Bruce Arians' tenure.
Gunter, Rucker in 2016
The 2016 season started quite differently than the 2015 season did for both Gunter and Rucker, who found themselves as critical pieces in the Cardinals' defensive line rotation, but not in the starting roles they were accustomed to.
Gunter was initially pegged as the Cardinals' second team nose tackle heading into 2015, but the injury to Peters forced Arizona's fourth round draft choice into the starting lineup early in his rookie season. Though Gunter fared well in his role last year, he was probably best suited to the rotational duties he took on this season because he's still technically quite raw. However, Gunter does demonstrate a quick first step at the line of scrimmage and impressive change of direction skills that made him a quality asset for the team each of the last two seasons.
Rucker actually sat out for much of training camp with an injury, which delayed his progress and likely allowed Mauro to overtake him on the depth chart. Though Rucker has far more experience than Mauro, he appeared to have lost a step late in his career and doesn't possess the brute strength Mauro brings to the table as a run-stopper.
Ultimately, 2016 served as a transitional season for Rucker, as he likely wasn't capable of handling the demanding workload of a starter this late in his career, but was still able to help the team as a rotational tackle in spurts.
Gunter, Rucker in 2017
With Peters set to enter the final year of his contract and Mauro signing a two-year extension to return to the Cardinals in early January, Gunter may find himself as the team's fourth or five defensive lineman in 2017.
Still, Gunter may earn a spot in the starting lineup if the Cardinals wind up placing their faith in 2016 first round draft choice Robert Nkemdiche. Should Arizona allow Campbell to walk in free agency and come to a late realization that Nkemdiche isn't ready to handle the rigors of a starting role, then Gunter could slide in as a defensive end in the team's 3-4 scheme.
Though it's more likely Gunter continues to serve as a backup to Peters as the team's nose tackle, like Mauro, Gunter does have the versatility to play every position along the Cardinals' defensive line and that makes him a valuable asset moving forward, especially because he's still playing out his rookie contract.
As for Rucker, his days with the Cardinals are likely numbered, and his days in the NFL may be over as well. At the age of 33, Rucker has played 11 NFL seasons and spent the last four with the Cardinals, but he only served as a primary starter for one of those campaigns. At this point, unless Rucker has a really strong desire to continue playing, it's unlikely he'll receive a significant opportunity for playing time with another NFL franchise.