EUGENE -- Every spring, with recruiting in a lull, the regular season still months away and free time relatively abundant, Oregon's football staff gathers to find what went right, what didn't and which changes can improve efficiency.

It's time used for self-reflection on the state of Ducks football.

Yet even well before the spring arrives, key offseason questions already have following a 9-4 season that kept Oregon, at No. 19, in the AP top 25 for a nation-leading ninth consecutive season, yet marked its lowest ranking since 2007.

The most pressing concern is whether Oregon's 115th-ranked scoring defense will improve incrementally or substantially under new coordinator Brady Hoke.

Hoke, a former Ball State linebacker, cut his teeth as an assistant coaching the defensive line or linebackers before spending the past 12 seasons as a head coach at Ball State, San Diego State and, most recently from 2011-14, Michigan. He has never been a college coordinator but was "intimately involved in every defense" as head coach, UO's Mark Helfrich said, and has a reputation as a turnaround artist after the Wolverines jumped from a woeful 107th in points allowed to sixth during his first season.

Hoke will oversee a scheme change to a 4-3 bereft of much starting experience at linebacker and without the benefit of DeForest Buckner, a constant on an inconsistent defense in 2015 who is now off to become a first-round pick in the NFL draft after winning Pac-12 defensive player of the year honors.

"Guys like Jonah Moi, Torrodney Prevot, Justin Hollins, all those guys that were kind of space guys (at outside linebacker) will now probably be that open end guy, strong-side end," Helfrich said Wednesday. "When Jonah Moi gets through this cycle, he probably ... will be that type of guy."

A key factor in Oregon's defensive improvement will be the play of a secondary that found itself literally on the receiving end of the bulk of UO's trouble. Pass-heavy Pac-12 offenses took notice as Oregon replaced a veteran-laden unit with underclassmen.

All but one of those players -- little-used redshirt freshman defensive back Glen Ihenacho, who has left the program -- will return, assuming Charles Nelson continues to play both ways under Hoke and new offensive coordinator Matt Lubick.

The good news for the Ducks is the precedent for such a second-year leap in the secondary. Past "D-Boyz" units coached by John Neal featuring Walter Thurmond, Jairus Byrd, T.J. Ward and Patrick Chung -- and later followed by a unit headlined by Ifo Ekpre-Olomu, Erick Dargan and Troy Hill -- all took their lumps early but steadily began sealing off open throwing lanes. UO's young defensive backs often appeared out of position last fall.

Why Hoke saw this job as the right fit is another question -- other than an appearance on his former SiriusXM radio show, Hoke has yet to comment since his hire Jan. 16 -- considering that in 2011, as Michigan coach, he told the Omaha World-Herald that practicing against pro-style offenses was more beneficial for the growth of a defense.

"It really puts your defense at a disadvantage when you're a spread offense, because every day you're going against a finesse offense," Hoke said then. "You become a finesse team. Defensively, the last thing you want to be is a finesse defense. You want to be able to get downhill and knock the snot out of people."

In the spring at Oregon, Hoke will get his first taste of practicing against an uptempo offense during uptempo practices. During a handful of two-hour fall camp practices last fall, UO was said to have run more than 150 plays.

Who earns the bulk of those reps isn't much in doubt. Graduate transfer quarterback Dakota Prukop is expected to win the starting job after his All-America junior season at Montana State, and he already is enrolled and working out with his teammates. Even with Friday's medical retirement of running back Thomas Tyner, a former five-star recruit who gained 1,284 in two seasons, the starting QB will be surrounded by a deep corps of skill-position talent headlined by Royce Freeman, the best single-season rusher in UO history with 1,838 yards in 2015.

But as Oregon's collapse from a 31-point lead in the Alamo Bowl showed, the success of its enviable stockpile of playmakers hinges on the consistency of the first two players to handle the ball each play.

Oregon is searching not only for new starters at quarterback and center, where Jake Hanson has been identified by teammates as a potential multiyear starter, but also consistent play from backups at those positions, too.

At quarterback, Jeff Lockie and Taylor Alie, who were inconsistent as backups last fall, will challenge for backup duty once again alongside redshirt freshman Travis Jonsen and incoming freshmen Terry Wilson (who will be in Eugene by the start of spring practices) and Justin Herbert.

UO will address those questions on offense under the guidance of Lubick, a first-time coordinator whose debut was the Alamo Bowl, and new quarterbacks coach David Yost, who spent the past three seasons coaching receivers at Washington State after nearly two decades tutoring quarterbacks.

"You've got to have great quarterback play in college football," Helfrich said.

About that, there is no question.

-- Andrew Greif

agreif@oregonian.com

@andrewgreif