The Nittany Lions are entering yet another season with a new defensive coordinator after Tom Allen departed for Clemson at the end of last year. Since joining James Franklin’s staff in late January, Jim Knowles has made an immediate impact inside Penn State’s football facilities.

He arrived in Happy Valley fresh off a national championship, having led an Ohio State defense that allowed just 12 points per game in 2024. His presence has already made a strong impression on both players and coaches.

“He’s got a great defensive mind, he’s fun to be around, and he brings tremendous energy to the room,” defensive backs coach Terry Smith said.

Knowles got to work immediately upon arriving, installing an entirely new defensive system for the Nittany Lions during spring practice. Known for his complex schemes, Knowles has refined the art of teaching his defense — having successfully implemented it at Oklahoma State, Duke, and most recently, Ohio State.

“I think in today’s game of football, defenses need to be somewhat complicated because you need to have answers for everything,” Knowles said. “Offenses in college don’t run the same things they do in the NFL, so you better have all different kinds of answers. But the key point is in teaching and installing the system, and I’ve gotten better at that. Coming into a situation like this, our charge is to be great now. If I can’t get it installed in a way that the players pick it up quickly, then it’s my fault.”

His emphasis on clarity hasn’t gone unnoticed by his players.

“Coach Knowles is, I kid you not, probably one of the smartest coaches I’ve ever met,” defensive back King Mack said, who rejoined the Nittany Lions after playing a lone season at Alabama. “He explains the defense in the simplest way for us.”

Knowles’ 2024 defensive scheme featured a versatile and aggressive 4-2-5 base, often described as a hybrid front, that leaned heavily on man coverage and highlighted the secondary’s ability to make plays—a trait he’s already recognized in his new group at Penn State.

“Those guys are playmakers. I’m going to set things up for them to make plays. I’ve seen it already in two days; they are a real strength of our defense,” Knowles said.

A key component of that scheme was the rover position, a hybrid safety role built for versatility and disruption. At Ohio State, Knowles deployed All-American Caleb Downs in that spot, giving him the freedom to roam across the field and wreak havoc at every level of the defense.

Penn State’s safety room is led by Zakee Wheatley, who stepped up in the absence of KJ Winston last season. The veteran safety tallied 96 tackles, three interceptions, seven passes defended, four pass breakups, and a sack in 2024.

Meanwhile, the second starting safety spot is up for grabs, with sophomore Dejuan Lane and Mack competing for the role.

“They’re both going to play a lot of football for us,” Smith said. “They’ll decide with their camp play who starts and who doesn’t.”

Returning starter A.J. Harris will lead the cornerback group, with Elliot Washington II expected to start opposite him. Zion Tracy, working at nickelback, has also been ‘running with the ones,’ according to coach Justin Lustig.

Knowles also made it a point to highlight true freshman Daryus Dixon, while acknowledging his secondary.

“The new guy, who should still be in high school – if I had to use one word, it would be impressive,” he said.

The secondary has drawn early praise from the new playcaller as the “real strength” of the unit. Penn State’s back end is looking to make a name for itself under Knowles.

“We’re excited to have him (Knowles) here, and we’re working hard to become the No. 1 defense in the country,” Smith said.

All eyes will be on how the Knowles-led defense performs when Penn State opens the season against Nevada at 3:30 p.m. on Saturday, Aug. 30, in Beaver Stadium.