Nothing's a given in college football, but one thing that's becoming routine is Alabama, Clemson and Oklahoma as playoff participants.

All three of those programs have tons of talent but major questions entering spring practices, and there are plenty of other storylines as programs across the nation kick off their 15 allowed sessions before the long days of workouts, camp and film study.

With the recent free-agency feel to college football, a lot of major programs are breaking in new faces at the quarterback position. Other Power Five programs have new coaches who are old, familiar faces.

Then, still another powerhouse said goodbye to a legendary coach and will replace him with an apt pupil who's been studying under him in Columbus, Ohio, for the past several years.

There's no shortage of headline-making stories across the country, and it all means college football is heating back up, at least for a little while.

Let's take a look at some of the top things to watch at college football's spring practices and heading into the bulk of the spring games.

Clemson's New-Look Defensive Line

Everybody wanted to talk about Clemson's high-powered offensive attack in 2018, and there was good reason for that as freshman quarterback Trevor Lawrence, dynamic running back Travis Etienne and a stable of awesome receivers led the Tigers to a national championship.

But the defense was no slouch.

Coordinator Brent Venables has a ton of budding stars on this year's defense, but he's losing more talent along the defensive front than most programs boast in a decade.

Gone are defensive ends Clelin Ferrell and Austin Bryant along with a trio of impact defensive tackles in Dexter Lawrence, Christian Wilkins and Albert Huggins. All declared for April's NFL draft in Nashville, Tennessee.

How do you replace all that? With studs. And that's just what Venables has at his disposal.

It all starts with elite defensive end Xavier Thomas, who should be on everybody's breakout list after the 5-star recruit started his career with 43 tackles, 10.5 tackles for loss and 3.5 sacks in a backup role as a true freshman. He's going to be a premiere defender this year with more reps.

Thomas isn't alone. Justin Foster and K.J. Henry will split time at the other end, and though the defensive tackles won't be anywhere near as elite as they were a season ago, Nyles Pinckney, Jordan Williams, Darnell Jefferies and Xavier Kelly have plenty of potential.

It's also a big deal that 4-star Tyler Davis is one of the team's numerous early enrollees, and the athletic freshman could break into the two-deep right away.

The Tigers won't be as deep or versatile up front as they were a year ago, but they still have the players to be very good. The development begins this spring.

A Brand-New Day

Nobody is going to say Ohio State will be better at football without Urban Meyer in 2019; that would be ridiculous. The Buckeyes were the beneficiary of the legendary coach's return to the sport after a brief retirement, and he put together seven incredible seasons.

In that time, the Buckeyes went an unreal 83-9 and won a national championship in 2014. They came close to several more.

Now, Meyer is gone, and replacing him is offensive assistant Ryan Day, who looks like he could be an up-and-coming star. Things won't be as much of a slam dunk as usual, but that isn't a bad thing.

The Buckeyes still have a bunch of talent, and Day's program should be much different than Meyer's. Already, he's made changes to his staff, replacing defensive coordinator Greg Schiano in favor of former Michigan defensive line coach Greg Mattison.

On offense, former Oklahoma State coordinator Mike Yurcich is injecting new life as the passing-game coordinator and quarterbacks coach. He's one of five new Buckeyes assistants. Oh, yeah, and dual-threat 5-star Georgia Bulldogs transfer Justin Fields is replacing record-breaking quarterback Dwayne Haskins, who entered the 2019 draft.

It's a new day, and everybody should be intrigued with how things are going to look. Even Day has to adjust.

"I do have to force myself to walk over to the defensive side every now and again just to make sure I am keeping an eye on all that because my natural reaction is to go right to the quarterbacks and get those guys going," Day told The Lantern's Colin Gay.

This spring will give us our first glimpse at the new-look Buckeyes.

Jalen Hurts, Justin Fields and a Slew of New Stomping Grounds

Justin Fields is far from the only high-profile player who'll have to get the lay of new land.

Perhaps college football's top "free agent" was Alabama graduate transfer quarterback Jalen Hurts, who is hoping to become the latest in a line of Oklahoma head coach Lincoln Riley's reclamation-project-turned-Heisman-Trophy-winning quarterbacks.

The Sooners helped Baker Mayfield and Kyler Murray resurrect their careers, and Hurts left Tuscaloosa, Alabama, for his final season rather than back up Tua Tagovailoa again. Hurts' tantalizing SEC Championship Game rally against Georgia in December has set exciting expectations.

Can he keep the Sooners rolling and boost his pro potential? His quest begins as he acclimates to the playmakers in a new set of crimson jerseys. 

Others will follow suit.

Georgia transfer Jacob Eason returned home to Washington after he couldn't beat out Jake Fromm, and he looks like the top candidate to replace Jake Browning for head coach Chris Petersen's Huskies. That's a storyline that shouldn't be overshadowed. Washington is the reigning Pac-12 champion, after all.

Eason isn't the only big-name transfer who'll take part in the Apple Cup. Former Eastern Washington quarterback and two-time Walter Payton Award finalist Gage Gubrud will try to be the next Gardner Minshew II while playing his final season with head coach Mike Leach and Washington State.

Notre Dame transfer Brandon Wimbush will try to keep Central Florida steered down the national championship conversation with McKenzie Milton recovering from an injury. 

Former Clemson quarterback Kelly Bryant will step in for Drew Lock at Missouri, while Tate Martell transferred from Ohio State to Miami and is awaiting the NCAA's word on whether he can play right away. Another former Clemson signal-caller, Hunter Johnson, is at Northwestern, and Ben Hicks left SMU to rejoin former Mustangs head coach Chad Morris at Arkansas.

Got all that? Yeah, it's going to take awhile.

Washington's Makeover

Nobody should discount what Jake Browning meant to Washington as a four-year starter in Seattle. He helped Chris Petersen rebuild that proud program into the best one in the Pac-12.

Now, he's gone, and so are a lot of his old running mates. What's next as this new crop of talent tries to expand on the program's recent success?

Fans are thrilled to see Jacob Eason and his huge arm. And they are curious to see if he can live up to the major talent he was as a 5-star recruit who left for the SEC, where he started for the Bulldogs as a true freshman before an injury as a sophomore set Fromm's career in motion.

If Eason (who is the heavy favorite to win the gig) doesn't get the job, it's because another talented player beat him. Jake Haener was Browning's backup, and though there are better prospects in the race, he's steady.

Jacob Sirmon and Colson Yankoff (both redshirt freshmen) are good-looking prospects, and incoming true freshman Dylan Morris is a Kellen Moore clone who surely hopes to have a college career as prolific as the former Boise State quarterback's.

Plenty of other position battles loom. Who is going to replace running back Myles Gaskin, who, like Browning, was a four-year starter? Salvon Ahmed, Kamari Pleasant and Sean McGrew give Petersen a variety of options.

That's not even considering the defense, which will get a major face lift in '19. Nine starters are gone, including leading tackler Ben Burr-Kirven, D-line sack specialist Greg Gaines and elite secondary members Byron Murphy and Taylor Rapp.

Petersen will essentially have a new group of playmakers in 2019. Will that be good news, or will it open the door for somebody else to seize the conference?

Can Alabama's Defense Return to Championship Form?

With Tua Tagovailoa and all those offensive weapons in 2018, the Alabama Crimson Tide were good enough to win a national championship. 

Tosh Lupoi's defense simply didn't cut it.

That's one of the reasons Lupoi is now with the Cleveland Browns as a defensive line coach and Alabama head coach Nick Saban went in another direction. The Tide promoted Pete Golding to defensive coordinator, and Saban plucked Tennessee assistant Charles Kelly from coach Jeremy Pruitt's staff to be an associate defensive coordinator in Tuscaloosa.

He hopes that's a winning formula, and Saban certainly sounded pleased about the makeup of his staff this month, per the Montgomery Advertiser's Alex Byington.

"Look, Charles Kelly was a guy that I've oftentimes considered being a coordinator here. I thought Pete did a really good job last year and should be the coordinator, but I also thought that Charles Kelly would be somebody who could do that (job) because he's been in our system with other people—(including) Jeremy (Pruitt and Jimbo Fisher) at Florida State, (and) Jeremy again at Tennessee."

The Tide have loads of defensive talent, and they just signed the nation's No. 1 recruiting class again. Butkus Award favorite Dylan Moses leads a group of linebackers who need to improve in '19.

Anfernee Jennings, Terrell Lewis and Christopher Allen could be stars. Markail Benton and incoming freshman Shane Lee could boost things, as could Joshua McMillon, who has waited his turn for four years. Eyabi Anoma, Cameron Latu and Jarez Parks have a ton of promise too.

The Tide have to replace guys such as probable top-five NFL draft pick Quinnen Williams and tackling machine Mack Wilson. The secondary has holes too. But Saban's specialty is the development of players on the back end, and Patrick Surtain II should shine in his second year.

Alabama has the top talent in the nation, and it's time to see if the new coaches can mesh with the players and create a championship formula for the third time in five years. 

Finding the Next Big Thing

One thing you can always count on in college football is a freshman phenom (or multiple freshman phenoms) showing out once the lights come on.

Last year, there were many, but guys such as Texas' Caden Sterns, Nebraska's Adrian Martinez and USC's Amon-Ra St. Brown (among others) had big first seasons. Oh, yeah, and a long-haired gunslinger at Clemson named Trevor Lawrence and receiver Justyn Ross had decent seasons too.

So, who are going to be the next big things?

The spring is a good time to identify prime candidates.

With Alex Hornibrook entering the transfer portal, Graham Mertz's path to the starting quarterback job at Wisconsin just got a lot clearer. Manny Wilkins' departure at Arizona State following his redshirt senior campaign paved the way for Jayden Daniels to jump into the starting gig in the desert.

LSU's secondary is in good hands with 5-star Derek Stingley, who is on campus and already turning heads in Baton Rouge. He's an elite talent who could start right away with Greedy Williams off to the NFL.

With North Carolina starting a new/old regime with the return of Mack Brown as head coach, freshman quarterback Sam Howell will have a lot of reps and a ton of attention this spring. New Oklahoma receiver and 5-star recruit Jadon Haselwood will be catching passes from Jalen Hurts, and Bru McCoy can help Texas right away if he's eligible.

Though running backs like Alabama's Trey Sanders and LSU's John Emery Jr. could make their marks soon enough, Michigan's Zach Charbonnet is already on campus. Tennessee's offensive line got a boost with 5-star Wanya Morris, who already is receiving starting reps at left tackle, per Michael Wayne Bratton of Saturday Down South.

There are numerous possible instant-impact players to watch, and it's just a matter of time before they start making their marks.

Welcome Back

Not every welcome-back story was roses a season ago. UCLA's Chip Kelly has yet to break through on the field and the recruiting trail, but one of the old-timers who had a hiatus away from the game had a promising first season.

That, of course, was Arizona State's Herm Edwards, who led the Sun Devils to a bowl game and then signed an impressive recruiting class.

Kelly probably will be fine, and Edwards is tracking well. Now, there are couple of remember-me hires in 2019. The Kansas Jayhawks made headlines when they brought on former LSU coach Les Miles to lead the program.

Perhaps even more interesting was North Carolina's decision to turn back the clock and convince Mack Brown to return to coaching after he spent years in the ESPN broadcast booth. Brown had last coached Texas in 2013, but he was the Tar Heels' coach from 1988-97.

Brown already made an impact on the recruiting trail, turning around a class that was devoid of impact players under Larry Fedora. Sledding is going to be a lot tougher in Lawrence for Miles, but he will have the opportunity to rebuild the Jayhawks (4-20 over the last two campaigns).

Optimism abounds.

"It's fun to see the enthusiasm right now for football at the University of North Carolina," Brown said after his first practice, according to 247Sports' Ross Martin.

Though the Jayhawks have roster issues, Miles seems intrigued by his offensive playmakers. "We have a number of guys that can play," Miles said, per KUSports.com's Benton Smith.

Neither coach is going to lead his team to a 2019 championship, but both are veterans who've built successful programs before. They'll have their schools back in the spotlight if for no other reason than their presences there.

Will JT Daniels and New Offensive Coordinator Graham Harrell Mesh?

Let's face it: 2018 was a miserable season for the USC Trojans (5-7).

You can use the excuse that they were young (which is true), and they were breaking in a lot of new players at important positions (also true). But not making a bowl game is unacceptable, regardless of the circumstances.

When you factor in how poor the Pac-12 was in 2018 and that the Trojans lost to hated, also-struggling rival UCLA, it's no wonder head coach Clay Helton was on slippery footing to close the season. Athletic director Lynn Swann kept him at the helm, and more tumultuous waters followed.

The Bruins fired offensive coordinator Tee Martin and then made a huge splash hire by luring former Texas Tech head coach Kliff Kingsbury to be the new offensive coordinator, only to see him leave to be the head coach of the NFL's Arizona Cardinals.

Bru McCoy, a 5-star signee, transferred to Texas before even taking a spring snap, and longtime impact receiver commitment Puka Nacua flipped to the Washington Huskies. Yeah, it's been a bad year.

But Helton made a smart, savvy hire in tabbing North Texas offensive coordinator Graham Harrell to be his OC. How Harrell's relationship with quarterback JT Daniels blossoms and how Daniels develops will directly impact Helton's job.

It's easy to forget Daniels was supposed to be a high school senior in 2018 but reclassified. Yes, he had some brutal games, but he also flashed his immense talent. With Harrell's Air Raid past, the two could be dynamic together. It's something Harrell is counting on.

"The reason I came here was because there aren't many times in your career that you have a chance to be at a place you have legit chances to win national championships year in and year out," he said, according to the Orange County Register's Joey Kaufman, "and if you ever get one of those schools, you better jump on it, because you may never get it again."

Texas' Secondary Needs to Be the Primary Focus

It didn't take long for head coach Tom Herman to bring Texas back to the brink of the national conversation. Last season's resounding upset of Georgia in the Sugar Bowl has cemented expectations for 2019.

Can the Longhorns compete for the national title?

With quarterback Sam Ehlinger at the helm, it's possible. But the Longhorns desperately need to improve their secondary, which finally began to show glimpses of promise toward the end of the season. Texas still finished just 110th out of 130 FBS programs, allowing 261.4 passing yards per game.

Yes, part of that is because they're nestled in the pass-happy Big 12. But just think how good they could have been if they'd been 50 spots better.

They lost 34-29 to Maryland, 38-35 to Oklahoma State, 42-41 to West Virginia and 39-27 to Oklahoma. In those setbacks, they allowed an average of 328 yards, 14 first downs and three touchdowns through the air per game.

The Longhorns have too much talent for those numbers. Senior Brandon Jones and rising star Caden Sterns—both starting defensive backs—are returning. B.J. Foster is a rising sophomore with loads of potential. The Horns lost Kris Boyd, Davante Davis and P.J. Locke III, but they have talented options.

Anthony Cook and Jalen Green are former elite cornerback prospects who could shine. Incoming freshman Kenyatta Watson II along with 4-star safeties Tyler Owens and Chris Adimora will arrive this spring.

Jones is out this spring following surgery, and some of the youngsters aren't on campus yet. But that just means other players will get valuable reps. With Texas retooling the linebacking corps as well, the secondary has to morph into a strength. That starts this spring.

Notre Dame's Regrouping Running Game

Notre Dame enjoyed a near-magical season in 2018, going undefeated until it faced Clemson in the College Football Playoff.

Everything came crashing to a screeching halt in a 30-3 setback, but that shouldn't take away anything from a brilliant rebound season for head coach Brian Kelly's program. With quarterback Ian Book and a lot of pieces returning in '19, the Fighting Irish want to build off the momentum.

One valuable piece who has departed, however, is Dexter Williams, who ran for a team-leading 995 yards and scored 13 total touchdowns.

The cupboard isn't bare behind him, though, and the Irish must find dependable weapons who can take his carries and match (or perhaps even exceed) his production. Returning players who will help fill the void are Tony Jones Jr. (392 yards and three touchdowns) and Jafar Armstrong (383 yards and seven touchdowns).

Armstrong especially is an intriguing option who also had 14 receptions out of the backfield and flashed all-around ability. He's a former receiver who could do some tantalizing things.

Behind him are even more options who could break out. Avery Davis is a converted quarterback, and incoming true freshman Kyren Williams is a versatile player who should get some carries. That's not even counting redshirt freshmen Jahmir Smith and C'Bo Flemister.

New running backs coach Lance Taylor replaced Autry Denson, who was hired to be Charleston Southern's head coach, and he's going to have a lot of options. The key will be finding Williams' replacements and diversifying the attack.

The Irish have plenty of runners who can make things difficult on defenders if they use them the right way. This spring is going to be an acclimation period for the new players and coach.

Are These Feleipe Franks' Gators?

Casual observers may not realize just how close the Florida Gators were to handing the keys of the offense to another signal-caller in 2018.

It may be a good thing that didn't happen.

After Missouri trounced his team, head coach Dan Mullen opened up the QB competition for the South Carolina matchup, but Kyle Trask suffered a season-ending foot injury in practices.

In the final four-game stretch of the season (wins over the Gamecocks, Idaho, Florida State and Michigan in the Peach Bowl), Franks threw for 862 yards (216 per game), ran for 177 yards and accounted for 12 total touchdowns and no interceptions.

That was enough to cement him as the Gators' quarterback of the present and the future, right? Nope. Mullen said this spring is going to be a wide-open battle between Franks, Trask and dynamic redshirt freshman Emory Jones, and early enrollee Jalon Jones is in the mix too, per Thomas Goldkamp of 247Sports:

"It's still a wide-open battle, it always will be. Every position is wide-open in the spring. I've always run the program that way. Last time I was at Florida it was a wide-open battle between Tim Tebow and Cam Newton and Johnny Brantley. It was just as wide-open then, I guess Tim was coming off winning the Heisman Trophy. Just as wide-open then as it is today."

With Mullen's reference to that "battle" everybody knew Tebow would win, is it really a competition? Can Franks re-establish himself as the man who is supposed to lead the Gators for the next year or two?

Franks is a 6'6" signal-caller who showed plenty of athleticism running the ball, but he's still not the type of quarterback Mullen normally employs. If he doesn't win the job, it will be interesting to see how Florida's offense changes.

New Playmakers Wanted in Happy Valley

There's no denying the 2018 football season was disappointing for head coach James Franklin and the Penn State Nittany Lions. Closing the season with a 27-24 loss to Kentucky in the Citrus Bowl was the cap to a season full of question marks.

Now, the Nittany Lions have to move on from the Trace McSorley era. The quarterback made a lot of plays in Happy Valley during his career, and even though last year wasn't his best, he'll be a big loss. Miles Sanders ran for 1,274 yards and nine touchdowns in the unenviable task of replacing Saquon Barkley.

He's gone too after declaring for the 2019 draft.

So, the result of a pivotal crossroad rests on a lot of new faces. Will PSU find a way to be better offensively with a different group, or will the team regress? This spring may go a little way toward telling us.

Tommy Stevens is the favorite to win the quarterback battle, and the 6'5", 240-pound redshirt senior has four years in the program already. Still, he's completed just 24 passes in three years and has 506 rushing yards and 304 passing yards. 

Sean Clifford, Will Levis, Michael Shuster and incoming freshmen Michael Johnson Jr. and Taquan Roberson will contend for Stevens' job this spring, but the Lions need better playmakers around their signal-caller.

A pair of former elite prospects are possible candidates to be stars. There's no question speedy running back Ricky Slade is a weapon who needs a lot of touches in this rebuilding offense, while former 5-star receiver Justin Shorter struggled in his first year in Happy Valley and needs to blossom.

Franklin needs to prove he's the coach to lead Penn State into bigger and better things. With Ohio State entering a new regime and Michigan still unable to win the big game, the door is open. 

All recruiting information is from 247Sports, and rankings are from the 247Sports composite.

Brad Shepard covers college football for Bleacher Report. You can follow him on Twitter, @Brad_Shepard.