Clancy Pendergast sits in a classroom on the first floor of the John McKay Center on a recent Friday afternoon. It serves as a rather appropriate setting, considering the 45-year-old defensive coordinator has some teaching to do.

Looking up · USC Defensive Coordinator Clancy Pendergast has plenty of experience, including a yearlong stint with the Kansas City Chiefs. — Courtesy of Kansas City Star

His lesson plan, as he points out, includes instructing USC’s defense to be aggressive, swarm to the ball, tackle and force turnovers. The primary goal, he says, is simply “to get our guys to play fast.”

The checklist, of course, sounds a bit lengthy.

It’s extensive, if only because the Trojans have particularly struggled on that side of the ball in recent years. Just last season, the unit allowed 394 yards per game (ranking 60th nationally) and 24.3 points per game (40th nationally). Most glaringly, in a Nov. 3 home game against Oregon, they gave up 62 points and 730 yards — the most points and yards given up in a single game in school history. It appeared to epitomize everything that had gone wrong with the group since the turn of the decade: slow reacting, slow adjusting — just slow, mostly.

Not to mention two years earlier, in 2010, USC allowed, on average, 400 yards per game, the worst mark since the school first began tracking the statistic in the mid-1950s.

Pendergast shrugs it off. He isn’t interested in discussing the numbers, not at length and not on this day anyway. In his mind, it’s irrelevant.

“I had my own things going; I really didn’t look closely at what they did,” said Pendergast, who joined USC head coach Lane Kiffin’s staff on Jan. 18 after spending the last three seasons heading the defense at Cal. “I’m looking forward into the future and not back.”

What Pendergast and Kiffin hope the future holds is this: that USC can adjust to the rising number of Pac-12 teams utilizing spread offenses — an obstacle the outgoing Monte Kiffin, the team’s de facto defensive coordinator, seemingly could not overcome. Teams such as Arizona, Oregon and UCLA all moved the ball with relative ease against the Trojans last season, employing spread systems that produced touchdown upon touchdown.

“That’s what makes it so challenging to coach in the [Pac-12]: the diversity of offenses that you face,” Pendergast said. “That’s also one of the reasons I enjoy coaching in this league.”

So, at present, with USC in its second week of spring practice, Pendergast is emphasizing a revamped defense. The program is breaking away from its traditional 4-3 defensive front, which utilizes four defensive linemen combined with three linebackers, in favor of a 3-4 scheme as part of that adjustment geared toward stopping speed in space.

“It’s the way to go in this conference,” Kiffin said. “It’s why we made the change.”

The exact defensive installation so far revolves around a “5-2” defense, a variation of the 3-4 that moves two linebackers up and closer to the line of scrimmage. Call it an aggressive approach, less reactive compared to the famed “bend but don’t break” Tampa-2 system favored under Monte Kiffin.

Pendergast seems confident it’ll work.

“It’s multiple and it’s flexible to use the personnel that we have,” he explained.

He’s conveyed that message often in recent weeks. He emphasizes the personnel available and a willingness to play anyone at any age at any position — a link to USC’s defensive heyday in the mid-2000s under Pete Carroll, who frequently played underclassmen without a second thought.

“The game’s about the players,” Pendergast said. “I don’t know any coaches who have ever blocked or tackled or had an interception. It’s a player’s game. Regardless of the style of offense, we want the best guys out there.”

Players say they’ve warmed up to the approach.

“He demands a lot out of the whole unit,” redshirt junior safety Josh Shaw said. “That’s what you want out of your [defensive] coordinator. Like I said, he’s hands-on. We’ve definitely responded well to him.”

Pendergast also quickly cites his resume, which serves as a sign he can fix the Trojans’ ailments. During his first season with Cal, the Golden Bears jumped from seventh to first in the then-Pac-10 in total defense. And in 2008, as the defensive coordinator for the Arizona Cardinals, Pendergast led his unit to fifth in the NFL in takeaways with 30 en route to a run to Super Bowl XLIII — a testament to his aggressive scheme.

“The guy has a lot of insight,” Shaw added. “His knowledge is unbelievable.”

For USC to bounce back in 2013, the team’s best hope is that his knowledge is as good as advertised.