Heading into fall camp of the 2016 season, ASU knew the competitions to replace graduated defensive starters like Jordan Simone, Lloyd Carrington and Antonio Longino would have a profound impact on the shape of the Sun Devils' defense this season.
While ASU had plenty of time to anticipate the personnel turnover at key positions like safety, cornerback and Devil backer, the Sun Devils didn't know they would have to fill two other significant defensive voids.
But less than two quarters into the team's season-opener against Northern Arizona, that's the position head coach Todd Graham and his coaching staff found themselves in, as senior Sam linebacker Salamo Fiso and junior Will linebacker Christian Sam were both unable to compete.
Fiso, who led the Sun Devils with 101 tackles in 2015, missed the first three games of the season due to an academics-related suspension.
Sam, meanwhile, suffered a season-ending ankle injury early in the second quarter against Northern Arizona that left the Sun Devils without their second-leading tackler for the duration of the year.
In the cases of players like Simone, Carrington and Longino, ASU had the entire slate of spring practices and all of fall camp to hand pick their replacements. But with Fiso and Sam out for considerable amounts of time, the Sun Devils suddenly had 197 tackles from the 2015 season wiped off the board, and ASU was forced to start from scratch.
While Fiso would return in late September for a month, he had barely regained his stamina by the time he suffered a knee injury that kept him out of two more games and limited his effectiveness when he came back for ASU's last two contests.
With two of its defensive leaders and a pair of the team's top pro prospects out or limited for much of the season, the heart of the team's defense broke apart, crushing ASU's hopes of a defensive resurgence after a dismal 2015 season.
With Sam out and Fiso constrained by a suspension and later an injury, the Sun Devils' on-the-fly adjustments at inside linebacker turned a perceived strength of ASU's team into an obvious weakness.
For much of the season, junior D.J. Calhoun, who played mainly in ASU's nickel package last season, became the Sun Devils' primary tackler, serving as an every down player at the Will linebacker position.
For parts of the year, Devil backer Alani Latu transitioned back to Sam linebacker, and split time with fifth-year senior Carlos Mendoza despite neither having the capabilities to replace Fiso's instinctual run-stopping abilities.
With sophomore Khaylan Thomas taking a redshirt season as he recovered from a knee injury, ASU's depth was so depleted that the Sun Devils moved their best pass rusher, junior Devil backer Koron Crump, to the Sam linebacker position during Fiso's injury absence.
Desperate times call for desperate measures, and in 2016, the Sun Devils were left in a position to invent new measures to try to offset the personnel losses that devastated the team's inside linebacker unit.
Ultimately, ASU learned it didn't have the means to replace both Sam and Fiso, and when they went down, so too did the Sun Devils' defense.
What we learned
Throughout Graham's tenure at ASU, the Sun Devils' defense has annually produced some of the highest percentage of solo tackles of any team in the Pac-12, and in some seasons, the country.
For the most part, that held true this season, as no ASU defender recorded more than 17 assisted tackles (Calhoun). However, without Fiso and Sam in the lineup, no ASU defender recorded more than 77 total tackles, breaking a streak of four straight seasons in which ASU had at least one player with 100 tackles.
During Graham's tenure, Will linebacker Brandon Magee (113 tackles in 2012), Will linebacker Chris Young (112 tackles in 2013), field safety Damarious Randall (106 tackles in 2014), bandit safety Jordan Simone (100 tackles in 2014) and Fiso (101 tackles in 2015) all reached the 100-tackle plateau in a single season.
The achievement is impressive individually, but highlights the way the defense is constructed and showcases how key personnel losses can detract from ASU's defensive capabilities.
Each of the five players to record a 100-tackle season under Graham played positions at the heart of ASU's defense, positions that some coaches would call "alley players." An "alley player" is a defender whose responsibility is to fill the alley, or gap, opposing offenses attempt to run through.
In the case of Will and Sam linebackers, ASU uses the four players along the defensive front, the end, Tiger, nose and Devil backer, to occupy offensive linemen and fill gaps on run plays, allowing the Will and Sam to fill a running alley and record tackles.
In the cases of field and Bandit safeties, both players are responsible as secondary alley-fillers on run plays, and often responsible for filling the alley on replacement run plays like bubble screens on the perimeter of the field. While ASU--like any defense-- generally wants to avoid having its safeties be its two leading tacklers as Randall and Simone were in 2014, these players should generally finish slightly below the Will and Sam linebackers in the final tackle tally.
With the construction of ASU's defense in mind, 2016 served as a reminder as to just how integral alley players are to the overall success of Graham's defensive scheme.
Without Fiso and Sam on the field together this season, ASU never had its full stable of linebackers, and as a result, the team's tackling suffered. Calhoun ended up leading ASU with 77 tackles, while ASU's Bandit safety, Marcus Ball (64 tackles), and field safety Armand Perry (59 tackles), finished second and third on the team in tackles, respectively.
With Sam on the sidelines and Fiso in and out of action for much of the year, the void they left gave opposing offenses wide open alleys, where far too often, ASU had no one waiting on the other side.
Salamo Fiso: A four-year starter at Sam linebacker, Fiso earned a reputation as a fearless, run-stopping linebacker who consistently graded as one of the Sun Devils' best tacklers. After earning All-Pac-12 Honorable Mention honors as a sophomore, Fiso elevated his game in 2015 with a 101-tackle, 21.5 tackle-for-loss season that featured 6.0 sacks. What Fiso lacked as a coverage defender, he made up for against the run and his versatility in filling lanes against both inside runs and stretch plays was critical to ASU's defensive success. Fiso's absence in 2016 and his late-season injury hurt the Sun Devils in obvious ways, as his academic suspension provided ASU with an immediate setback at the beginning of the season. That type of mistake has largely been uncharacteristic of senior leadership figures during Graham's time at ASU, but Fiso never appeared to truly embrace a leadership role. While Graham considered Fiso the most important defensive communicator of his tenure, the games he missed in 2016 forced ASU to begin to transition the communication responsibilities to different players on the Sun Devils' defense.
Carlos Mendoza: A fifth-year senior who spent much of his career battling injuries, Mendoza enjoyed the best season of his tenure with the Sun Devils in 2016 as he saw most of his playing time filling in during Fiso's absences. Mendoza finished the season with 26 tackles and 1.0 sack, and provided ASU with spurts of energy at various points during the year. Though Mendoza didn't have the speed to assist ASU much in coverage or the strength to take on blockers in running lanes, he did demonstrate impressive perseverance by working his way back to full health this season and giving ASU a depth option off the bench.
Christian Sam: Perhaps the best NFL prospect on ASU's defense, Sam's injury crushed the Sun Devils' linebacker depth and left the team's defense without a top returning player poised for the best season of his career. Sam's ability to stop the run nearly mirrored Fiso's in 2015, but Sam is far and away the top pass defender of ASU's inside linebackers and his coverage skills were greatly missed by the Sun Devils this season. When Sam was healthy in fall camp, ASU spent time exploring options of how it could group Fiso, Calhoun and Sam together at once in the same defensive personnel package, which could have given the Sun Devils an added edge on that side of the ball. Instead, Sam and Fiso never played a down together this season, as a devastating ankle injury suffered in the first half of ASU's season-opener left Sam in a position where he will likely be able to receive a redshirt year. If Sam is able to return healthy next season, his presence should give ASU an immediate defensive boost at a position where depth turned into a serious issue in 2016.
D.J. Calhoun: A key asset in ASU's nickel package in 2015, Calhoun's best work in the program has come on passing downs as a blitzer in the Sun Devils' pressure packages. Calhoun led the Sun Devils with 77 tackles this season, and became the starting Will linebacker immediately following Sam's injury. Though Calhoun provided ASU's defense with a handful of highlight-reel hits, his tendency to attempt to crush opposing ballcarriers with devastating blows led to a high volume of missed tackles on opponents' explosive plays. Calhoun served as an alley player in 2016, but his stats suffered compared to Will linebackers of the past because he doesn't read running lanes particularly well and has a hard time shaking off of blocks once he's engaged. For Calhoun to take a step forward next season, he may consider streamlining his physique to improve his coverage capabilities as well as focusing on his fundamental approach against the run.
Khaylan Thomas: A 4-star recruit out of Etiwanda High (California), ASU elected to burn Thomas' redshirt last season and use him on special teams. However, this spring, Thomas underwent a knee procedure and his recovery process extended well into the regular season, at which point ASU decided to use 2016 as Thomas' redshirt season. Had Thomas been available to play, ASU likely would have benefitted from his presence as a depth option, but now, the Sun Devils can focus on preparing Thomas for a larger role in 2017 with a full slate of spring practices this offseason. Thomas has good size for an inside linebacker prospect at 6-foot-2 and 228 pounds, and before his injury, he demonstrated the speed to aid ASU from a coverage standpoint as a linebacker. Still, it's uncertain how Thomas will fare in his return from injury, but ASU is hoping he'll be able to compete for extended playing time in his sophomore season.
Koron Crump and Malik Lawal: We mentioned both Crump and Lawal as potential Devil backers in our last position review, but both players could also end up at inside linebacker next season depending on the direction ASU's coaching staff wants to take with its front seven. During Fiso's injury absence, Crump moved to Sam linebacker and demonstrated intriguing potential from a speed and athleticism standpoint, but he didn't showcase the type of run-stopping abilities ASU is accustomed to having at its inside linebacker positions. If Crump adds weight this offseason, practices at the position and demonstrates a knack for understanding key reads, he'll likely fare much better at inside linebacker than he did during his short time at the position in 2016. As for Lawal, he traded back and forth between position groups for much of the season, and his frame is probably best suited for the Will linebacker position. If ASU is able to keep some combination of Sam, Calhoun and Crump on the field at inside linebacker next season, then the Sun Devils could explore the option of using Lawal in the same capacity that Calhoun played in ASU's nickel package in 2015. If neither player ends up at inside linebacker next season, then ASU will likely have to hit on at least one junior college target during this recruiting cycle to ensure that the unit has enough depth heading into 2017.