There’s a lot for USC’s defense to digest this spring

A no-huddle, up-tempo offense is not the only new scheme USC Coach Steve Sarkisian and his staff are installing this spring.

Defensive coordinator Justin Wilcox is implementing a 3-4 defense with new terminology and multiple variations.

On Thursday, after the Trojans’ second workout, Wilcox said defensive players were adapting quickly to the concepts and to facing approximately 120 plays each day.

“When you start adding those up, it grows pretty fast and it can get a little fuzzy — especially when it’s all new,” Wilcox said. “They will continue to get better and better.”

Last season, running a “52” hybrid scheme, former defensive coordinator Clancy Pendergast molded the Trojans into the Pac-12 Conference’s top-ranked statistical unit. The Trojans, who did not play Oregon or Washington, ranked 13th nationally in total defense.

After he was hired in December, Sarkisian did not retain Pendergast, opting instead to bring Wilcox, linebackers coach Peter Sirmon and secondary coach Keith Heyward from Washington. The Huskies ranked sixth in the Pac-12 and 55th nationally in total defense in 2013.

Trojans players said the transition to the new defensive staff has been smooth, and that basic football concepts remain the same.

Senior linebacker Hayes Pullard said the 3-4 and the 5-2 schemes were “partners in crime.”

“You line up 11 against 11,” he said.

The lanky Wilcox, 37, has been a visible and dynamic presence during workouts. It’s a marked contrast to the 46-year-old Pendergast’s mostly low-key demeanor.

“He’s a lot younger,” defensive lineman Leonard Williams said of Wilcox, “so he’s out there running around with us a lot more.”

The other noteworthy change on the defensive side, of course, is the absence of Ed Orgeron. The former defensive line coach — who served as interim coach after Lane Kiffin was fired — famously pushed his charges with a voice that rumbled through the practice facility and beyond.

But defensive line coach Chris Wilson, who worked last season at Georgia, has made his presence felt in the meeting rooms and on the field, Williams said.

Williams and senior cornerback Josh Shaw are among the defensive players who are sitting out or are limited while recovering from surgeries or injuries.

Senior J.R. Tavai and sophomores Jabari Ruffin, Quinton Powell and Scott Starr are listed as outside linebackers. All are getting work at what Wilcox described as the “rush position.”

Defensive players, Wilcox said, are benefiting physically and mentally from practicing against the up-tempo offense, “where it’s the ninth play in a row ... and you’ve got go out and play with great technique and great fundamentals just like you did on the first snap.”

The Trojans will practice in shoulder pads for the first time Saturday and then will be off for a week for spring break.

Sarkisian said the Trojans would not scrimmage until after their sixth practice. When they do, it probably will be done during the course of a workout.

“We’re going to tackle and we’re going to play football, but I don’t know if it will be for an extended two-hour period,” he said. “I think it will be broken up within a practice and we’ll be efficient when we do it.”

gary.klein@latimes.com

Twitter: @latimesklein