After three weeks of preseason, there is one definitive conclusion to draw about the USC defense, several questions that can only be answered once the games begin and some more intangible considerations that one can value as they so choose.

What seems certain is that the Trojans are going to have a very entertaining pass rush.

Junior outside linebacker Drake Jackson has looked determined to prove himself as a first-round draft pick while causing consistent havoc in the backfield this month. Five-star freshman defensive end Korey Foreman is going to be eased in as he grasps the full breadth of the scheme, but he will get an immediate opportunity on clear passing downs to do what he does best and try to get to the quarterback. And moving along the defensive line, sophomore Tuli Tuipulotu is a prime breakout candidate who is already playing beyond his years, while redshirt senior Nick Figueroa is actually the Trojans' reigning sacks/tackles for loss leader.

The rest of the defense? Well, there are some questions. That doesn't mean the Trojans don't already have some of the answers, it's just that the actual test hasn't come yet so it's hard to truly know.

Much has been made about the unusual nose tackle situation USC finds itself in, not only losing its multi-year starter to the NFL in Marlon Tuipulotu but then subsequently losing the top three candidates to replace him -- veteran Brandon Pili to a torn Achilles, freshman Jay Toia to UCLA via transfer after the spring, and Alabama transfer Ishmael Sopsher to a lengthy rehab process after surgery on his leg.

The coaches have consistently dismissed any concern about filling that void -- redshirt freshman Jamar Sekona and redshirt sophomore Stanley Ta'ufo'ou will rotate there -- but have acknowledged some trepidation about the lack of depth.

At linebacker, redshirt senior Kana'i Mauga is an intriguing playmaker who just has to show more consistency in his overall game, while junior Ralen Goforth and redshirt junior Raymond Scott round out the three-man rotation at the position, both also with plenty to prove.

Redshirt senior safety Isaiah Pola-Mao had an impressive preseason, but beyond him the Trojans are relying on redshirt junior Chase Williams -- similar to some other players mentioned as a guy who has played a good bit but needs to show more reliability -- and a bevy of freshmen and transfer newcomers.

And at cornerback, junior Chris Steele is a fairly proven commodity with the NFL in his sights while redshirt junior Isaac Taylor-Stuart shares the same goals this season but without the established track record.

So how does all of that add up collectively?

How one answers that question at this point largely hinges on the general confidence they have in defensive coordinator Todd Orlando.

Head coach Clay Helton has consistently talked about how Orlando and his staff were hamstrung by not having a spring practice or a normal build-up to the season last year, trying to introduce a new defense through that unusual pandemic year. He's noted the focus had to be on Xs and Os and putting in the scheme and not so much establishing an identity or mentality, and now going through a traditional spring and summer this year Helton says he's seen the difference.

"Really the personality of TO and the confidence of Coach Orlando is really rubbing off on those guys," he said this month.

Defensive line coach Vic So'oto offered a variation of that observation early in camp after the first practice in full pads.

"Our defense likes to hit a lot -- likes to hit. I think when we first got here it was different. I wouldn't say it was good or bad, but they've all bought into the run and hit style that Coach Orlando preaches and each one of the position [groups] speaks the same language," he said.

"I think it's all a mindset, it's all a mentality," safeties coach Craig Naivar said. "It's a level of what's expected and I believe the term is the standard's the standard. And getting guys to understand that and embrace that and understand the why behind it of what we're trying to accomplish behind that. Tough to accomplish last year with no spring ball and limited camp. Huge benefit to what our strength staff's done, those guys have done an amazing job. It's allowed our guys to be able to come out and do those things and consistently do that. They put armor on their bodies, they got more flexible and they got stronger."

Again, that's the nebulous intangible -- one can read into it what they choose. It was indeed a physical camp, though, and this defense does play fast. That much we can affirm.

USC was middle of the pack last season defensively, ranking 46th nationally in scoring defense at 26.0 points per game allowed (3.4 better than 2019) and 40th in total defense at 369.7 yards per game (an improvement of 38.8 YPG).

But if one buys into the notion that last year was not a true representation of what this defense can be under Orlando and that the real growth will come this fall, then it's relevant to reiterate the early returns from his last three jobs.

At Utah State, Orlando took over a defense in 2013 that was already successful, having ranked 14th nationally in total defense (322.1 yards per game) the previous season. Under Orlando, the unit remained stout, ranking 12th (330.9) in his first season.

In his first year at Houston, 2015, the defense actually dropped from 20th the previous season (343.4) to 53rd (383.6) before surging up to 13th nationally in 2016 (319.6). But one consistent theme of Orlando's defense is stopping the run, and that showed immediately at Houston as the Cougars ranked eighth nationally in 2015 in rush defense (108.9 YPG) and then fourth in 2016 (100.2). That 2016 Houston defense also ranked tied for 15th nationally in tackles for loss (7.69 per game) and tied for 19th in sacks (2.57 per game).

And in his first season at Texas in 2017, the Longhorns improved from 94th to 41st in total defense (365.6 YPG), and from 89th to 29th in scoring defense (21.2 PPG) while ranking eighth nationally in allowing 106.9 rushing yards per game and leading the country in both defensive touchdowns (7) and interceptions returned for a touchdown (5).

So on paper, yes, this defense has several points of uncertainty, but perhaps the equally significant unanswered question is how much better and more cohesive can this defense be as a collective now with a full year and a half in this system and buying into Orlando's philosophy?

That's the spectrum upon which a range of preseason predictions can be made, depending on which of those ends resonates more.

With that said, let's take a look at each position group and what we learned this preseason.

This might be both the strongest position group on the team and the one with the most glaring unknown.

As noted above, the pass rush is tantalizing.

Drake Jackson has 17 tackles for loss and 7.5 sacks over his first two seasons (including the shortened 2020 campaign), but it has never felt like he's truly tapped into his full potential. If his 2021 preseason performance is any indication, that could well happen this fall. Jackson has already said this is his "money year" and that he fully intends to leave for the NFL after this season, and it's possible he sends his draft stock soaring in the process. The junior OLB was our defensive camp MVP and we're full believers in him having a huge season.

As for five-star freshman DE Korey Foreman, he's battled groin and elbow issues this preseason, which have limited him at times, but he's mostly played through them and flashed his elite pass rush moves. He's still grasping the defense overall and has spent every unoccupied moment standing next to defensive line coach Vic So'oto for continuous instruction.

Helton indicated that Foreman will be brought along at his pace, but that he will be a factor immediately on third downs.

"TO has already mixed him into the third down packages because his first step and his pass rush ability. He’s still learning the defense on base downs, first and second down, but I know he can do one thing. He can rush the passer on third down," Helton said.

Meanwhile, redshirt senior Nick Figueroa, who had a team-high 7 TFL and 3.5 sacks in six games last season, will anchor that strongside defensive end spot with Foreman rotating in behind him.

Sophomore Tuli Tuipulotu, who put on 25 pounds since the spring, gives the Trojans the versatility of using him on the inside, and the ability to have Jackson, either Foreman or Figueroa and Tuipulotu on the field together is why we're so high on the defensive line overall.

As for the nose tackle spot? Well, it's hard to say how much of a concern that will prove to be. The depth is scary, though. If Jamar Sekona or Stanley Ta'ufo'ou have to miss any time with injury, the staff will really have to get creative there as they don't seem to think redshirt freshman Kobe Pepe is quite ready and Ishmael Sopsher remains out indefinitely.

"I'm confident in all the guys -- it just comes down to consistency. They can all do it, but finding who can do it the best over and over and over again, that's where we're at," So'oto said.

Projected DL depth chart

Strongside DE

1. Nick Figueroa, redshirt senior

2. Korey Foreman, freshman

DT

1. Tuli Tuipulotu, sophomore

2. Jake Lichtenstein, redshirt junior

NT

1A. Jamar Sekona, redshirt freshman

1B. Stanley Ta'ufo'ou, redshirt sophomore

B-backer (technically an OLB)

1. Drake Jackson, junior

2. Hunter Echols, redshirt senior