Excused from the session a week ago, Nassib walked briskly across a parking lot behind the practice facility with his head down and school books that looked more like matchboxes tucked under his long arms. He seemed alarmed to see nearly 30 people close to his vehicle.
It was coincidence. Nassib had parked next to the black iron gate that separates the practice fields from the parking lot where reporters wait each Wednesday and they were just as surprised to see him on their side.
''Had a chemistry test,'' Nassib said, before jamming himself into his smallish Ford Escape and driving off.
It was a rare close encounter with arguably the country's most disruptive defender who has politely declined interview requests throughout his career. It took a visit from ESPN this week to get him talking as Nassib was featured on the network's ''Big Man on Campus'' spot. Other than that, he's remained elusive despite being the center of attention for opposing offensive coordinators this season.
Crazy Carl as his teammates call him leads the country with 10 sacks, five forced fumbles and is on pace for the most sacks in a season since Louisville's Elvis Dumervil had 20 in 2005, heading into Saturday's game against No. 1 Ohio State. Not bad for a player who walked onto the team without a scholarship offer from an FBS team out of high school.
''He just got his shot,'' safety Jordan Lucas said. ''He worked very hard for it and he's continuing to work hard for it and it's showing in his play and it's showing in the numbers. Carl, he's nuts.''
But in a good way.
''He's got that nickname Crazy Carl because his intensity is unmatched every single play,'' sophomore defensive end Garrett Sickels said.
A fifth-year senior, Nassib has been selected to the All-Academic Big Ten team twice while majoring in biology. He wants to attend medical school, but those plans have been muddied by his gridiron emergence. He's expressed a desire to play as long as he can if possible and that is looking more likely each week.
His ascension seemed unlikely considering he never started a game at any level before this season and walked on to Joe Paterno's final team in 2011 as a 6-foot-4, 215-pounder.
He was still a self-described ''skinny'' nobody two years later when Bill O'Brien's first recruits arrived on campus. But Nassib's relentless attitude caused scholarship offensive tackle Andrew Nelson to take notice.
''I remember thinking, this guy is pretty hard to block and no one is really talking about him,'' Nelson said. ''But he's a pretty good player, and you just saw that development continue each year.''
Two sit-downs with O'Brien before the 2013 season helped.
During the first one in winter workouts, O'Brien told Nassib he'd play on special teams if he bulked up. So he did, hitting the weight room five days a week and twice on Saturdays that summer to add nearly 50 pounds of muscle. The second one came in training camp after O'Brien saw a transformed Nassib beating his scholarship tackles on the practice fields. He called Nassib to his office midway through camp. Nassib feared he'd be ruled ineligible because he forgot to pay his tuition bill. But he wouldn't have to worry about it. O'Brien brought him in to tell him he'd earned a scholarship.
That year was really Nassib's breakout season, his teammates say. He added a fiery presence to the team's coverage and return units and made the most of his limited snaps.
Nassib and Sickels have made defensive end a strong spot for Penn State, even after losing three key players off last year's team. While Sickels was redshirting last season, Nassib helped him stay focus.
''He's taught me that you can never get down on yourself,'' Sickels said. ''The big thing with him is you have to have the most intensity every single play, you can't take a play off.''