Greg Roman, in his first year as the 49ers’ offensive coordinator, talks gleefully about learning at the foot of innovator Paul Brown, for whom he once served as a gofer.

Roman’s face lights up at the mention of Bill Walsh, whose tapes he studied after being granted access to the 49ers’ video archives. “Just awesome. He was a brilliant guy, a brilliant guy,” he said.

But ask about one of Roman’s minor influences — a former Central Intelligence Agency profiler who specializes in the psychology of violence — and you’re going to need security clearance.

“Can you turn that off?” Roman said, eyeing a reporter’s tape recorder.

Click! It’s the first of several times that Roman goes undercover. If this interview were a military document, large sections would be “redacted” in thick black ink.

Here’s what isn’t a state secret: When Roman was a student at John Carroll University, near Cleveland, he and a handful of his teammates became enraptured by Dr. Thomas Evans, a terrorism expert whose violence and aggression class is among the most popular on campus. “We hit it off, and he took us under his wing,” Roman says now.

Evans would meet with players outside of class to share strategies from his CIA days that might translate to the football field. The emphasis wasn’t military strategy but rather mental preparation, with Evans urging players to energize their “animal brain” for maximum reaction time. He also taught them how to overcome the traditional limits of pain and fatigue.

Evans’ contributions were so substantial that when John Carroll finished with an 8-1 record and captured a share the 1994 Ohio Athletic Conference (Division III) title, players rewarded their teacher with the football equivalent of a shiny red apple. “My first and only championship ring,” Evans said in a phone interview.

Roman, who spent the past two seasons under Jim Harbaugh at Stanford before following him to the NFL, would never put his old terrorism professor on a par with his football influences. Still, the lessons about combat-type mentality stuck with him.

After a recent 49ers practice, he recalled Evans as “a brilliant guy who had an amazing amount of real-time experience. He was a big help, really. I learned how to focus and really narrow my thinking down to what was necessary.

“What I learned from (Evans) definitely influences how I communicate today,” he said.

Then Roman catches himself.

“Can you turn that off again?”

On the phone from his office in the John Carroll psychology department, Evans speaks with a deep and gravelly voice. In style and substance, he evokes Peter Graves, the actor from “Mission: Impossible.”

Now 70, the professor said he first became intrigued by the link between neuropsychology and physical performance as a young Marine “at a time when they could really beat the hell out of you. It’s amazing how you can find a way to push through four or five more miles when there’s a drill sergeant right behind you.”

In his classes, he explains how the brain chemically responds to combat stimuli and how the mind can be trained to handle such situations with maximum efficiency.

Those lessons had obvious appeal for a group of undersized John Carroll football players looking for any edge they could get against conference powerhouse Mount Union.

They sought out Evans after class, and the professor, a former high school wrestler and martial arts practitioner, was more than happy to show them how to think like warriors.

Step one was reprogramming their concept of physical limitations. One of his favorite tricks is to get someone lifting weights to “scramble the number of reps in their head” so that they lose track of how many they’ve done. Evans said that when people don’t fixate on a number, they improve by at least 30 percent over counting the reps.

Evans also guided them through mental imagery sessions — one former player called it a “deep meditation” — before games. That might include techniques for blocking out pain. Quarterback P.J. Insana says now that he played through a broken nose and cracked ribs that season, sometimes re-entering a game after consulting Evans on the sideline. “There’s a reason I finished those games,” he said.

Roman is loath to give up details, but other players of that era say Evans got them into a hyper state of alertness.

“You’d go into a game in a controlled state, calm — a ‘3’ — just like we’re talking right now,” recalled Matt Warnement, who played on the defensive line next to Roman. “Then you’d go from a ‘3’ to a ’10’ when the ball was snapped, and stay that way for about 5 seconds — the average length of a football play. Then you’d do it over again.”

Did it work? Roman’s senior class was the last at John Carroll to earn a piece of the title; Mount Union has won the outright conference championship every season since.

“There was a noticeable difference — there wasn’t even a question,” Evans recalled. “You saw a real difference in what I would call ‘motivated candidates.’ I can’t make a bad athlete good. But I can take a good athlete and fine-tune him.”

Roman was the ultimate “motivated candidate.” He arrived at John Carroll after a hardscrabble childhood in Ventnor, N.J., bringing with him an intensity rarely seen at the private Jesuit school of about 4,000 students.

Roman was particularly maniacal in the weight room. One teammate recalled him doing 450 pounds on the bench press. Another said he saw him do a 700-pound squat.

Roman was listed on the roster as 5-foot-8.

“There’s a line in the movie ‘A Bronx Tale’ where somebody says, ‘The saddest thing in life is wasted talent,’ ” former John Carroll receiver Sean Williams said. “Well, Greg totally epitomizes the opposite of that — not wasting a thing.”

Matt Canning, a former John Carroll cornerback who remains one of Roman’s closest friends, remembered the lineman doing “squats until he puked” and then grabbing a 100-pound dumbbell and carrying it around the gym. “If you worked out with Greg,” Canning said, “you were in for a long day.”

But Roman knew more than squat. He had a 3.5 GPA at John Carroll and carried that intellectual approach to the football field. He had life-transforming teachers long before Evans’ lecture hall. Roman, through family connections, studied X’s and O’s from Brown, the Hall of Fame coach and seminal figure for the Cleveland Browns and Cincinnati Bengals.

Roman’s uncle, Jack Clary, is an award-winning author who cowrote Brown’s autobiography, “PB: The Paul Brown Story.” Clary helped Roman get a job as Brown’s little assistant as early as the seventh grade. Greg tagged along with Brown on several occasions, ranging from Bengals training camps to the week leading up to Super Bowl XXIII against the 49ers.

Roman proved indispensable. “Yeah, I’d go get him a Tab. Remember Tab?” he said with a laugh.

Brown liked the kid’s company and nicknamed him “Little Chunk.” Roman, meanwhile, honed his eavesdropping skills. He would sit with Brown in his luxury suite on Bengals game days and follow him around during practices.

“I would just listen, listen, listen,” Roman recalled. “Being around somebody like that, you become a great listener in a hurry, you know? So much wisdom. Those eyes have seen a lot of football.”

From Brown, Roman learned the intricacies of an offensive system that Walsh later refined and popularized as the West Coast offense.

Whatever it’s called, it’s the system Roman will be resurrecting with the 49ers after helping Stanford bedazzle Pac-10 opponents the past two seasons. The Cardinal averaged 40.3 points per game last year, more than double the 49ers output.

Roman said that he — not Harbaugh — will be the primary play caller. But the kid who listened, listened, listened as a kid never grew out of that habit. “If anyone has a good suggestion, my ears are always open,” he said.

For now, Roman is in no hurry to disclose more details. Like Harbaugh, he clams up rather than disclose information an opponent might use against him. The 49ers were intentionally bland with their play calling during the exhibition season, with Roman speaking cryptically about his red-zone tactics. “Whether or not we call those plays in the regular season is anybody’s guess,” Roman said. “We’ll wait and see on that.”

Somewhere, a former CIA agent is smiling.