After taking the kinds of losses the USC defense did after the 2008 season, big changes were going to happen.
Up front on the defensive side of the ball, USC will have a new coach and at least two new starters. Plus, some players with redemption on their mind will get a chance to prove they belong.
But despite the changes, the Trojans could have one of the quickest lines they've had in years.
Calling the 2008 Trojan defense dominant could be an understatement, and like with any great defense, that dominance started up front.
Anchored by defensive end Kyle Moore and defensive tackle Fili Moala, the USC defensive line helped hold nine opponents under 100 yards rushing.
The Trojans also got to the quarterback 29 times on the year, led by Moore's five sacks.
While the numbers were good (opposing teams gained 221.8 yards per game last season and averaged just 9.0 points per game), there was plenty of personnel turnover along the line.
Everson Griffen and Averell Spicer both started the Trojans' first three games, but after Oregon State upset USC, both became backups. In their place, Clay Matthews and Christian Tupou stepped in and held onto the starting spot for the rest of the season.
Matthews, Moala and Moore are all gone to the NFL, and Nick Holt left to become the defensive coordinator at Washington. Jethro Franklin retuned to the staff from the NFL, replacing Holt and David Watson as the defensive line coach.
Griffen talked about working with Franklin after one of USC's spring practices when the line spent a ton of time in the offensive backfield.
"I just think we came out fired up because Jethro makes sure we're fired up on all cylinders," he said. "He's an upbeat coach, and he makes sure we're ready to go at all times. We came out here ready to go. He's always on our butt to be 100 percent at all times; we did that today."
Griffen has evolved from an underachiever with amazing talent to a budding leader on the line.
"I've got to be the leader of the d-line," he said. "It's my junior year, and it's time for me to change. This is a good opportunity. We've got a good d-line coach coming in. Jethro's just awesome. We've got some hogs on the line, and I couldn't be more excited."
While Griffen has led vocally, Spicer, the only senior of the group, has a different approach.
"I feel a weight on my shoulders. I have to lead by example. When we're out here working out, I'm not talking too much. I want to lead by example instead of just running my mouth," Spicer said. "Everson was always going to be a leader. He's just so talented. He's pretty vocal. He definitely likes to get it going and talk a little bit. The defense needs that."
"I've got to start," Casey said. "I've got a hard time thinking about coming off the bench one more year. It was hard for me to come off the bench last year. This year, I want to come out with a bang."
Casey will likely have one of his closest friends on the field with him in Armstead after the coaching staff decided to switch the big sophomore over from defensive tackle, where he was a strong candidate to replace Moala.
"I think the move went pretty well. I picked up some stuff pretty well, but I don't think I'm anywhere near my potential at the position," he said. "I think with the extra practices coming up, I could be really good."
On the edge, Armstead could get help in pass-rush situations from Jackson. Wes Horton and Nick Perry both redshirted and also could contribute right away.
Griffen still has some maturing to do, but he seems serious when he talks about becoming a leader on the defensive line. Likewise, Spicer sounds very motivated to put together a good season because his back is against the wall.
The Casey-Tupou battle at nose tackle will end with USC putting a very talented player on the field either way it goes.
There are some questions about Armstead at defensive end, but the early indications are that he could be a force on the outside. His combination of size and speed make him a unique weapon for Franklin and the defensive staff.
There's tons of depth here with Jackson, Perry, Kennard and Fangupo. USC will have some tough redshirt choices to make, but in the end, there will be talent to spare.
While this line isn't dotted with big names like Sedrick Ellis, Lawrence Jackson, Moala, Moore and Matthews, this group has a chance to be even faster and more prolific - especially against the pass.
Change, in this case, may end up being a good thing.