Chicago — While Michigan State was busy rolling through a dominant three-year stretch, winning a pair of Big Ten championships and reaching the College Football Playoff, there was one constant with the defense – it was going to get after the quarterback.

In 2013, the year the Spartans beat Ohio State in the conference title game and followed that with a win over Stanford in the Rose Bowl, the defense sacked the quarterback 32 times. A year later, that number jumped to 42 with Michigan State beating Baylor in the Cotton Bowl.

And in 2015, with another Big Ten championship won before falling to Alabama in the playoffs, the Spartans piled up 37 sacks.

That sort of production nearly ground to a halt in 2016 as Michigan State managed just 11 sacks, one of biggest reasons the Spartans fell middle of the pack in the conference in total defense and won just three games all season.

A lot of it fell on the defensive end position as Shilique Calhoun and Lawrence Thomas were off to the NFL leaving the Spartans thin on experience. And with Josh King and Auston Robertson no longer with the team, it’s a wide-open battle headed into preseason camp and one that will be vitally important.

“The end position is built around pressure on the quarterback,” coach Mark Dantonio said. “I think the RPO (run-pass option) things have negated some of that pressure.

“It’s a learning process there and those guys have to excel. Every great defense has to have players that excel there.”

Who might step up to get the sack numbers back to what the Spartans expect will be a focus of camp. Fifth-year senior Demetrius Cooper would be the first name, but he’s still working to get back on scholarship after off-field issues.

After that, it’s up in the air. Former walk-on Kenny Willekes has been impressive since last spring while the likes of sophomore Justice Alexander and junior Robert Bowers will get a chance to establish themselves.

“A lot of guys have played some and they have to reassert themselves and then we’ll see where we’re at,” Dantonio said.

There also could be an infusion of fresh faces.

Dantonio said this week that linebacker Brandon Randle has made the shift full-time to end after redshirting last season. Senior linebacker Chris Frey called Randle a “freak” of an athlete and even though he spent spring practice at linebacker, Randle (6-foot-2, 231 pounds) has the ability to make a quick transition.

“He’s a 4.4 guy, a 4.5 guy that weighs 230, 235 and can be a factor,” Dantonio said. “He can be a guy. He can be a factor, he can be a pass rush guy. He’s gotta continue to come. There are a lot of guys like that.”

Michigan State also recruited three defensive ends – Lashawn Paulino-Bell, DeAri Todd and Jacub Panasiuk. While Todd and Panasiuk will have a chance to prove themselves in preseason camp, things will move slower from Paulino-Bell.

Still recovering from a jet ski accident in the spring, Dantonio said they’ll be cautious with Paulino-Bell.

“I think he'll be able to make camp, but he's lost some weight so he's back to about 235 or 240," Dantonio said. "And he's young, so he just got back, he's just learning again. I think he's got a ways to go because there's a learning curve, so we'll see. I think only his level of strength (is a concern) right now because he's weak coming off the injuries.”

The Spartans have also shaken up coaching responsibilities in an effort to better handle the defensive line duties. Mark Snyder has moved from linebacker to take over the defensive ends while Ron Burton will focus on the interior of the defensive line.

With the way college football is played now, Dantonio said it was the best move to make as co-defensive coordinator Mike Tressel takes control of the linebackers.

“Defensive end play is a different now, even in a 4-3,” Dantonio said. “We also wanted to reduce the player-coach ratio on the defensive line, not have it 20-1 and more like 10-1.

“Ron Burton does a tremendous job, we just felt like defensive end, with all the RPOs at end, even the greatest pass rushers there are certain situations where they had to restart themselves. So they needed to be coached differently.”