USC’s football team has a long history of vaunted defensive players.Ronnie Lott. Junior Seau. Willie McGinest. Troy Polamalu. Clay Matthews III.And last year, USC Athletic Director Pat Haden argued that now-junior defensive end Leonard Williams belonged in that mix. Haden tweeted, “I have been around USC for over 40 years… Leonard is one of the top 5 players I have seen. He is that good.”Indeed, the Daytona Beach, Florida, native has been tearing it up since he got to USC in 2012. Last year, Williams became known as one of the best defensive players in the country. Williams played the whole season with a torn labrum and still racked up 74 total tackles and six sacks, wreaking havoc on opposing offenses.His standout season earned him a spot on five preseason award watchlists, including the Nagurski Trophy (top defensive player), the Bednarik Award (top defensive player) and the Lombardi Award (top lineman/linebacker).But Williams has been having a relatively quiet season so far. He came up big in USC’s upset of Stanford, including a sack of quarterback Tyler Hogan when the Cardinal were knocking on the door, but has been a nonfactor in most other games.Sophomore Su’a Cravens has been USC’s breakout player on defense this season, flourishing in a safety-Sam linebacker hybrid role. Williams, who entered the season amid rumors of being a Top-5 pick in the 2015 NFL Draft, might be suffering in the new defensive system. The Trojans just don’t produce sacks like they used to — USC’s eight sacks on the season is tied for 96th in the nation. Still, Williams is a team captain and one of the leaders of the defense, and will be key in calming the storm going forward.This week at practice, defensive coordinator Justin Wilcox begrudgingly characterized USC’s defense as “schizophrenic.” Indeed, USC’s defense went from holding Stanford to 10 points to giving up 452 rush yards to Boston College and 510 pass yards to Arizona State. This can be partially blamed on the coaching staff, as many have argued, but can also be fixed in part by USC’s leaders on defense, like Williams, taking control.Williams said at Pac-12 Media Day that he was just beginning to grow into his leadership position and that he was more likely to lead by example than to get on his teammates’ cases for missing tackles. But though Williams might be the headliner of the defense, he’s not alone out there.Linebacker Hayes Pullard, a fifth-year senior, has long been the Trojans’ emotional leader on defense. When he was ejected from USC’s game at Stanford after incurring a targeting penalty, it seemed that the Trojans rallied to replace their captain. Trojan fans wanted to believe that once Pullard entered in the second half of the BC game, it would immediately uplift the team and turn around the disastrous performance, but that fairy tale ending didn’t quite work out.With suspended senior defensive back Josh Shaw’s status still up in the air, Williams and Pullard need to take command of the defense, and Saturday’s matchup at Arizona is the perfect opportunity to do that. Aubrey Kragen is a senior majoring in communication. She is also the sports editor of the Daily Trojan. Her column, “Release the Kragen,” runs Fridays.