Ranking Pac-12's defensive triplets: No. 5 Washington State

With a tip of the cap to ESPN's Bill Barnwell, who assembled the team triplet rankings for pro football, we decided to do the same with the Pac-12. Here are the parameters: We’ve selected a trio of skill defensive players from each team in the conference.

The rules: Each player comes from a different position group, so the defensive version of this series features a player from the defensive line, linebacker group and secondary. We then ranked each program’s troika against the others in the Pac-12, and we’ll be unveiling and writing about each in reverse countdown order. We continue to No. 5 with the Washington State Cougars.

DL Hercules Mata'afa: He posted impressive numbers in 2015, especially considering the fact that he was a freshman: 11 tackles for loss and seven sacks. Mata'afa also earned a spot on one Freshman All-America team. He'll be counted on as the centerpiece of the Cougars' defensive line moving forward. Despite taking a stride forward in most categories under first-year coordinator Alex Grinch last season, Washington State's defense regressed against the run -- so Mata'afa will be asked to help stymie the flow of 4.9 yards per carry that the Cougars surrendered. That goal is certainly attainable now that he's bulked up to 250 pounds.

LB Peyton Pelluer: His father, grandfather and great-grandfather all played for Washington State, so it's only fitting that a born-and-bred Cougar led the team with 101 tackles last season. Pelluer is an exceptionally physical linebacker whom Washington State coaches and teammates frequently call "Butkus" in honor of the hard-hitting NFL Hall of Famer. Pelluer forced a pair of fumbles last year, making him a great exhibit of Grinch's newfound focus on takeaways.

SS Shalom Luani: Speaking of takeaways, Luani provided plenty in 2015: He intercepted four passes, racked up 123 return yards on those picks, and forced two fumbles. The Cougars tripled their takeaway count from a season prior -- 24 to 8 -- and Luani was the primary driver behind that effort. He also led the team with six pass break-ups and finished third on the roster with 90 tackles, so the valuable versatility is readily apparent here. Luani will be counted on to provide senior leadership for Washington State's improving secondary in 2016, and if he's able to replicate last season's impressive statistical output, the Cougars should be sitting pretty.

Evaluation: Plentiful credit for Washington State's surge to nine wins in 2015 should be given to the Cougars' defense, which demonstrated far more aggressiveness than it had in years prior. These three players were emblematic of that improvement on each level of the unit, and the trio should be expected to showcase further improvement in 2016. If that does indeed happen -- and if this group's supporting cast also follows suit with the upward trend -- then Washington State can be considered a legitimate Pac-12 North title contender. They certainly have the offense to be deemed a credible threat, and that defense is trending in the right direction thanks to players like these.