The USC Trojans are coming off a Pac-12 championship, but face plenty of uncertainty due to the departure of many key players to the NFL. This year will be a test for coaches and players as they look to retain their crown in a new-look Pac-12 landscape.

As always, the Trojans reload rather than rebuild.

What USC is able to accomplish in 2018 will be closely scrutinized by many, as some still have questions regarding head coach Clay Helton’s true ceiling and whether or not he was the beneficiary of a talented quarterback and team. Can Helton produce similar results when he doesn’t have a potential No. 1 overall draft pick at quarterback?

Apart from the talent that left for the NFL — we will come back to this later — USC has a number of high-quality players returning for another go; some to be featured more, others looking to showcase their talents following an injury in 2017. Then there are the young bucks looking to steal time and roles from veteran players dropping the ball. In all, the Trojans have a robust, talented, and relatively healthy squad headed into spring practice and beyond.

It’s not just the players looking across from the them that will have changed, there also have been some key losses and additions to Helton’s retinue as well. How these new coaches gel with the overall program will go a long way to determining the Trojans’ level of success. Fortunately there are several familiar faces, so the learning curve shouldn’t be too steep.

5 Storylines to Watch During USC’s Spring Practice

1. Who takes over for Sam Darnold? How long will that last?

USC has lost Darnold to the NFL and this means a couple things for quarterbacks Matt Fink and Jack Sears. One of the two is going to come out of spring having won the first of two battles that they will need to win for the job. The first is in the spring, the second comes later when highly touted freshman JT Daniels arrives on campus.

Whoever leads coming out of spring practice should have the advantage entering fall camp. Daniels reclassified and is scheduled to enroll this summer because he felt he had more than a puncher’s chance at being the starter. He has the support of many area pundits and it’s not terribly often you see reclassification at a high-profile program like USC, so regardless of what happens in the spring, this quarterback competition is far from over.

2. The Texas Tesla is gone, but what about the Carr?

Ronald Jones II came to USC with the intent of doing big things, which he did right out of the gates when he Charles White’s freshman rushing record. The Texas Tesla became a mainstay in the Trojan backfield and his running style became a favorite among those who love smash-mouth football mixed with elegance. Jones will now try his hand in the NFL, which leaves Stephen Carr to take the ball and run with it, literally.

Carr can beat you with style, grace, power or his hands. He had 363 rushing yards, 188 receiving yards and scored three touchdowns last season while receiving limited touches. He missed four straight games in October due to an injury. If he can hold up for the duration of a full season, Carr can and should do special things in Cardinal and Gold.

3. Who replaces Deontay Burnett?

From a blueshirt to a clutch and trusted receiver out of the slot, Burnett’s career as a wide receiver at USC is the stuff they write stories about in Hollywood after they happen in real life. Burnett was a prolific talent for the Trojans, coming up in big games and always finding holes in the defense. Whether it was against Stanford, Texas, Western Michigan or in disappointing losses to the likes of Notre Dame and Ohio State, Burnett could be counted on to leave it all on the field. If USC can churn out another spectacular slot receiver, whoever ends up being the starting quarterback will be the beneficiary.

There is a feeling that incoming freshman Amon-Ra St. Brown will come in during the fall and take the slot position by storm. St. Brown is an extremely talented receiver, but so are veterans Trevon Sidney, Velus Jones Jr. and Pie Young. USC honors those who have put in their time and effort, those three are going to get a fair shot and making a name for themselves in spring could go a long way toward changing some of the thinking about St. Brown.

4. Ever-changing coaching staff

There is a school of thought that says an ever-changing staff is a sign of a negative environment, but top programs are often poached for their talent among the coaching ranks just as much as they’re poached among the player ranks. This is precisely what happened with running backs coach Deland McCullough and the Kansas City Chiefs. He did wonders with the Trojan backs and the NFL took notice.

It took until the first week of March, but the Trojans finally hired a new/old running backs coach in Tim Drevno, who had spent the past three seasons at Michigan working under Jim Harbaugh. McCullough was only with the Trojans for one season, but he helped produce one of the nation’s top running backs in Jones while also developing Carr and some of the other younger guys at the position. Jones is gone, but the backfield cupboard is far from bare.

Drevno’s resume speaks for itself and there’s some familiarity given his brief stint at USC back in 2014. This spring will be more about getting to know his players while incorporating his ideas into Helton’s and establishing a rapport with the rest of the staff. The hope is that the groundwork can be laid to eventually produce more success in the running game this fall.

5. What does Tim Drevno’s hire mean for Neil Callaway?

Drevno’s arrival also could have a trickle-down effect elsewhere among the coaching staff. To that point, besides running backs coach, Drevno also will serve as run game and pass protection coordinator. At first glance, the latter part seems like a euphemism for offensive line coordinator. The key difference here would seem to be that Drevno will work with the offensive line on pass protection while Neil Callaway, the position coach, will continue to work with the linemen on an individual basis and make sure they are physically prepared. This is an educated guess as we won’t really know until we see the new dynamic play out on the field.

Callaway was hired without much fanfare and while fan appreciation is not yet a determining factor when it comes to support staff additions, in the case of USC it means extensive scrutiny and a fan base waiting for any poor performance or reason to hammer their point about Callaway home. Thus far, Callaway’s product has not been strong. USC allowed 30 sacks last year to rank 71st nationally. That won’t cut it in Troy and Drevo’s addition as the pass protection coordinator has a “the writing is on the wall” feel to it. Only time will tell.

— Written by Josh Webb, who is part of the Athlon Contributor Network and a sportswriter in Southern California. Webb also is a staff writer for @TheMarvelReport. Follow him on Twitter @FightOnTwist.