Gunther Cunningham is remembered as an “NFL lifer” who spent 34 seasons coaching in the league for six different franchises, including a two-year stint as the head coach of the Kansas City Chiefs.

The former Oregon linebacker broke into the coaching ranks as a graduate assistant at his alma mater a half-century ago under Jerry Frei.

Cunningham, who played for the Ducks from 1966-68, beginning with Len Casanova’s final season as head coach and then two seasons for Frei, died Saturday after a battle with cancer. He was 72.

“He wasn’t a very big guy, as far as football players go, but he was really active,” recalled teammate Claxton Welch, an Oregon running back from 1966-68 who won a Super Bowl ring with the Dallas Cowboys. “You could tell Gunther was always in the coaches’ offices looking at film.”

Cunningham was able to study the nuances of the game under Frei’s notable full-time staff, which included future NFL head coaches John Robinson and George Seifert. Longtime NFL defensive coordinator John Marshall also started as an Oregon assistant in 1969.

“I knew he had the passion,” said Jack Rust, who was Cunningham’s roommate during their Oregon playing days. “John Marshall came in the same time, and they were buddies. Seifert was my defensive coach. Bobby Moore came along. …

“It was quite a time to be a Duck. I remember talking to Gunther about that, being around all those great coaches and players.”

When Cunningham left Eugene to pursue his coaching dreams, he gave Rust his fishing boat.

After coaching in college for over a decade, including stops at Stanford (1973-76) and California (1977-80), and spending the 1981 season with the Hamilton Tiger-Cats of the CFL, Cunningham became a fixture on NFL sidelines from 1982-2016.

Following a successful run as Kansas City’s respected defensive coordinator, Cunningham was elevated to head coach in 1999 when Marty Schottenheimer resigned.

“He was intensity personified,” Carl Peterson, the general manager who promoted, fired and ultimately rehired Cunningham during two stints with the Chiefs, told the Kansas City Star. “A fully committed coach, and a brilliant defensive coordinator.”

Several of Cunningham’s former teammates say his fiery nature was on full display at Oregon.

“I did play a little bit of racquetball against him when he was a grad assistant,” recalled wide receiver Bob Newland (1968-70). “I had a bit of a wry sense of humor. I knew he was an intense guy, so I’d pick at him a little bit. I’d say something like, ‘I thought you were going to be quick enough to get that one.’

“He’d get hot and he’d be ready to go.”

Ken Woody, who lettered for the Ducks from 1968-70, quipped: “I refused to go in the racquetball room with him. There was only one exit, and he could block it.”

Keith Sherman also played linebacker at Oregon from 1966-68 and competed with Cunningham for the starting weak-side spot.

“He still owes me a case a beer from a tennis match that we had,” Sherman said. “He was a fierce competitor. He loved to compete and he was tough to beat. … He beat me out our sophomore year, and I beat him our our junior and senior year.”

During Cunningham’s three seasons as a player, the Ducks posted a 9-21 record.

One of the highlights of the 3-7 finish in 1966 was a 17-6 road win at the Air Force Academy. Cunningham made a 42-yard field goal in the thin air at Falcon Stadium (elevation 6,621 feet), which was the school record at the time.

“I kicked a couple of field goals in junior college before, short ones, about 17 yards. We’ll say this was my first real field goal,” Cunningham said in the book, ‘They Called Him Cas,’ authored by teammate George Dames. “Cas got kind of mad at me for not practicing kicking very much, so I decided to go at it hard and Tom (Trovato, the holder) told me to bite my shirt while I’m kicking to keep my head down.”

Cunningham, a square-toed kicker nicknamed “The Toe,” shifted his focus to linebacker after that season, which led to Woody winning the placekicking job.

“He was fierce,” Woody said. “He had to work hard to control his temper at times. When he did start coaching, he was all in. He was really fortunate to work around some really strong coaches. He really transformed into a very professional, smooth guy as the years went on. He was a player’s coach.

“That’s what I always ask about coaches is, ‘What do the players think?’ And the players thought a lot of him.”

Defensive lineman Mike Kish used to bring Cunningham to his house in California during summer break.

“That guy had an appetite,” Kish said of the German-born Cunningham, who became a naturalized U.S. citizen in 2010. “My mom was Italian. He’s German, not Italian, and she made meatballs.

“I remember my mom is smoking a cigarette saying, ‘Boy, can that guy eat meatballs.’”

Years later, Cunningham invited Kish to watch him coach against the Raiders in Oakland.

“I remember he said, ‘Can you believe I’m the head coach of the Kansas City Chiefs?’” Kish said.

Cunningham’s Oregon teammates were not surprised he became an NFL lifer.

“He was intense,” Rust said. “I’m glad he wasn’t my coach, but I’m sure glad he was a friend.”