If one wanted to try and understand how important senior linebacker Trey DePriest is to the University of Alabama defense a good starting point would be the season opener against West Virginia at the Georgia Dome.

DePriest didn’t play and his absence was noticeable. That’s not anything against interior linebackers Reggie Ragland and Reuben Foster, but both were making their first career starts while also being responsible for relaying the play calls in from the sideline, getting everyone lined up correctly, and …

At times the Mountaineers couldn’t snap the ball fast enough.

“I think some of the errors that we made in the first game were first-game jitters and not having Trey DePriest out there, who is the most experienced guy, to sort of control the front seven,” Coach Nick Saban said. “We have made improvement, which is what you want your team to do as a coach, and we’ll continue to do it.”

With so many new contributors improvement was already considered the key to Alabama’s defensive progression this season, but the learning curve was even more pronounced during the subsequent weeks. While Alabama still beat West Virginia 33-23, the Mountaineers tallied 365 passing yards. Through October no other opponent managed more than 251.

“He’s been leading everybody on the defense,” Ragland said. “Everybody responded really great.”

His presence has been crucial in the development of the linebacker corps as well. DePriest entered the fall having played in 40 games, with 26 starts for the Crimson Tide, while no one else was close in terms of experience or on-field production of 149 career tackles and 65 in 2013.

The closest was Denzel Devall, who started as the Jack linebacker (the hybrid outside linebacker/defensive end who frequently puts his hand on the ground) and was in on 30 tackles last season. Following him were Ragland (17), Dillon Lee (16), Xzavier Dickson (13), Reuben Foster (12) and Ryan Anderson (five).

The group was joined by early-enrollee freshman Shaun Dion Hamilton, who as an interior linebacker looked lost at times in the spring but did better than most in learning the basics of Saban’s defensive system run by coordinator Kirby Smart.

“That’s everybody who comes through here,” said DePriest, who was initially Dont’a Hightower’s understudy after arriving from Springfield, Ohio, as part of the recruiting Class of 2011. “(The defense is) just hard to learn. We learn different stuff every day, so it’s kind of rough to pick it up just like that.”

It was for DePriest during his first eye-opening spring.

“That’s exactly what it was,” said DePriest, who as a rookie played mostly on special teams. “I didn’t know anything. I was lost running around. Didn’t really know much, trying to learn as much as I could from Dont’a. That’s whom I really tried to learn from because Coach Smart can only do so much. But yeah I was lost.

“I’ve come a long way from my freshman year.”

With DePriest leading the way there’s been comparable improvement amongst his comrades. Ragland became that interior presence that seems to thrive in Saban’s system and was named a semifinalist for the Butkus Award (nation’s best linebacker) in late October. Outside linebackers Dickson and Anderson have made major contributions, especially in pass-rushing situations, and helped the Crimson Tide avoid having to take a step back when Devall was sidelined for three games by an ankle injury.

Similarly, the defense as a whole started to come together despite having just four players who are older than DePriest: defensive linemen Brandon Ivory and Anthony Orr, and safeties Nick Perry and Jarrick Williams.

This is Perry’s first season as a regular starter at free safety and Williams isn’t always on the field as the fifth defensive back in the nickel package, known in Saban’s scheme as “star.” Facing so many spread no-huddle, hurry-up offenses makes it difficult to regularly use a nose guard like Ivory, and Orr has never started.

Meanwhile, the Crimson Tide has enjoyed an increase of situational roles and deeper rotations, resulting in more players contributing as coaches continually look for ways to counter the variety of offenses faced. Thus the importance of having that veteran in the middle to be sort of the of quarterback of the defense was only stressed, especially when facing so many no-huddle, hurry-up spread attacks.

“We’ve been practicing it since January, February, whenever we started spring ball,” DePriest said about spread schemes, which gave Alabama problems against Auburn and Oklahoma at the end of last season. “So pretty much every day we’ve practiced against it, so that tells me it’s not really a problem.

“We were ready for it a year ago, but we just didn’t play it the way we wanted to play it.”

Perhaps that only contributed to DePriest’s decision to not leave early and enter the NFL Draft, while teammates like Adrian Hubbard and Vinnie Sunseri did despite not being considered top-round selections. Regardless, the reins were handed over from Butkus winner C.J. Mosley well before spring practices began.

“I didn’t regret my decision, I knew that’s what I wanted to do,” DePriest said. “It wasn’t necessarily all for football. I wanted to graduate. I’ll be the first one from my family to graduate from college. That’s something I wanted to do, and play some more college ball.”

Those family ties shouldn’t be overlooked as DePriest has been known to write names of loved ones on the fingers of his gloves, and part of his ritual prior to kickoff includes a quick phone call.

“I try to call my grandfather before every game, if I can get service, and get a prayer,” he said.

Usually someone with a phone in the locker room gets through, which is sort of like Alabama’s defensive philosophy for attacking quarterbacks this season. The Crimson Tide has had 13 different players contribute to a sack, and 22 with a tackle for a loss, but DePriest isn’t among them. Neither is defensive lineman A’Shawn Robinson, who led the Crimson Tide with 5.5 sacks in 2013.

Going back to that quarterback analogy, part of DePriest’s responsibilities is helping put his teammates in place to make plays, not necessarily himself, and opposing offenses aren’t going after him much either. There’s really nothing an offense can do that he hasn’t seen, so it’s tougher to get Alabama’s defense on its heels.

Consequently, from Arkansas’ final touchdown in the third quarter until the second quarter at Tennessee two Saturdays later, Alabama didn’t give up a single point and on 17 of the 34 possessions the opposing offense didn’t even record a first down. On the scoreboard the Crimson Tide scored 83 unanswered points, including the 59-0 shutout of Texas A&M.

“Other than the first game and giving up a few big plays in the Ole Miss game, our defense has played pretty consistently well all year,” Saban said.

Of course, the Crimson Tide could have simplified the defensive calls and adjustments this season, making it easier on the players at the cost of its effectiveness. It didn’t have to though because of the veteran who’s almost been like a coach on the field.

“No. No. Coach Smart wouldn’t do that,” DePriest said.