Since Oklahoma's disastrous blowout loss in the Cotton Bowl to Texas A&M, the program has lost:

• Three fired assistant coaches, which is pretty much unheard of since Bob Stoops became head coach 15 years ago;
• A four-year starter at quarterback;
• Its two leading receivers;
• Both starting safeties, including the leading tackler from a year ago;
• A left tackle who might be among the first 10 picks in April's NFL draft;
• Three defensive linemen with starting experience;
• A three-year starting cornerback;
• A three-year starting linebacker;
• And, for good measure, an elite punter.

That massive turnover provides the backdrop against which the Sooners will start spring practice on Saturday. The sentimental types among Sooner Nation may lament the loss of a number of accomplished stars. The more demanding among us could view it as a chance to inject some new blood into a program that has been good-but-not-quite-good-enough for four years, an eternity in Norman time.

Naturally, though, that kind of upheaval leaves plenty of questions to be answered as the young bucks assemble for spring ball. Chief among them:

The Sooners’ secondary was the strength of the defense last year, but only one starter, Aaron Colvin, will be around for 2013. As such, secondary coaches Mike Stoops and Bobby Jack Wright have some work to do this spring figuring out who's going to be in the mix this fall.

Colvin (6-0, 181), who opted to stay for his senior year, will be one of the leaders of the defense this year. He finished third on the team in 2012 with 61 tackles, 4 interceptions and 11 passes broken up.

The defensive backfield would have been stronger if safety Tony Jefferson had hung around for his senior year, but he opted for greener pastures in hopes of getting drafted by the NFL. Mike stated in OU’s spring football press conference Thursday that Gabe Lynn (6-0, 199, Sr.) would be the starting free safety going into spring camp. Lynn hasn't exactly lit it up in his OU career, but he has made some improvement since 2011. He appeared to make some strides as the full-time nickelback last year.

The Sooners’ defense will be a huge question mark this season, just as it was last year when the “D” had many folks scratching their heads. As is the case with the defensive line this spring, uncertainty is the dominant theme at linebacker.

There’s talk that defensive coordinator Mike Stoops is going to switch from the 4-3 to a 3-4 base defense. Whatever he does, he will need to get some consistency from his second line of defense. It got so bad with his 'backers a year ago that Mike was throwing out seven-man secondaries that proved useless against mobile quarterbacks.

One of the bigger developments this offseason at the position actually involves someone who won't be there this spring. Middle linebacker Tom Wort seemed lost in adjusting to Mike’s defensive scheme, prompting Wort to leave early for a possible stint in the NFL.

Just who is Jay Boulware, the latest hire by Bob Stoops to coach the tight ends and special teams?

For starters, he is a Longhorn. He was an offensive tackle for Texas in 1991-95. Can’t find any information if he was a starter or not, but he’s definitely a Longhorn. I guess we shouldn’t chastise him for that now that he has come over to the good guys. The Burnt Orange fans probably see things differently.

After he got a degree in Austin, he hung around and coached tight ends as a graduate assistant for the Steers from 1994-96. Pat Fitzgerald was one of his pupils. (No, not the one who coaches Northwestern.) Fitzgerald was an AP All-American in 1996, so there's that.

The Oklahoma Sooners are preparing to open up spring practice on Mar. 9 facing arguably more questions than any OU squad in recent memory. Jake Trotter of ESPN's SoonerNation joins Homerism for a podcast to preview all the latest news leading up to spring camp, including the addition of three new faces to the coaching staff.

Jake and I cover:

*What ultimately motivated Bob Stoops to make significant changes on the sidelines.

*What Bill Bedenbaugh, Jerry Montgomery and Jay Boulware bring to the program.

*The potential move to a 3-4 defense.

*Corey Nelson's disappearance in 2012 and how he can get back on the field.

*Assessing the odds in the quarterback derby.

*And more.

(Subscribe to Blatant Homerism's Podcast through iTunes. Please rate and review the show if you get the chance, too. Thanks.)

Other than quarterback, no other position this spring will face the same level of fan and media scrutiny as Oklahoma's defensive line. Everything we previously knew about the DL position has changed in the last three months.

Jackie Shipp is gone, replaced by Jerry Montgomery. Plus, no more waiting for multi-year contributors Stacey McGee or Jamarkus McFarland or Casey Walker to reach their potential.

The biggest question, though: What defensive scheme is OU going to run, 4-3 or 3-4?

The Sooners have a stacked backfield that is two-deep solid at both fullback and running back. Goals for this spring should include developing an expanded role for fullback Trey Millard and figuring out how OU's ball carriers will mesh with the planned involvement of the quarterback in the running game.

Fullback

Millard (6-2, 256, Sr.) and Aaron Ripkowski (6-1, 260, Jr.) are punishing blockers. Millard also has impressed running (33 carries, 198 yards) and catching the ball (30 receptions, 337 yards, 4 touchdowns). He’s not easy to bring down.

There may not be two position groups for Oklahoma on more diametric ends of the certainty spectrum this spring than wide receiver and tight end.

Mystery men at tight end

The TE position seemed almost non-existent in 2012, and there won't be any new signees coming to the rescue. If you're looking for a silver lining, we'll get a chance to see what new tight ends coach Jay Boulware can do.

In his first spring practices at Oklahoma, new offensive line coach Bill Bedenbaugh will have four starters back from last year and a few players who have playing experience as well. He recently told Jessica Coody of Sooner Sports TV that the best way to play the line is to be tough, physical, mean and nasty.

“I’m going to coach them hard and I expect them to be great,” he said.

But the problem isn’t that OU’s front wall isn’t tough and physical, because they had been tremendous in protecting Landry Jones in the pocket. The problem is that they hadn’t been mean and nasty when it comes to opening running lanes. Bedenbaugh, a former West Virginia line coach, is more of a spread offense guy, and the Sooners need to learn how to block better for the running game to develop.

Bob Stoops’ hire of Jerry Montgomery as defensive line coach doesn't seem as baffling as hiring Bill Bedenbaugh as o-line boss.

Montgomery and Bedenbaugh are supposed to be great recruiters. That’s fine and good, but a lot of time high school studs don’t turn into football stars on the collegiate level. Like Bedenbaugh, Montgomery's ability to coach 'em up is debatable.

Montgomery spent the last two years as Michigan’s d-line coach, and two years prior to that, he held the same position at Wyoming. Coaching the d-line the past four years for the Wolverines and Cowboys, Montgomery has produced no All-Americans and only one first-team all-conference honoree (tackle John Fletcher in 2009 at Wyoming). Defensive end Josh Biezuns was named to the Mountain West's second team a year later, and tackle Mike Martin was a second-team all-Big 10 honoree at Michigan.