Dennis Green, the former 49ers assistant and Stanford head coach who helped blaze the trail for African-Americans in what was then the Pac-10 Conference, has died at age 67 from “complications of cardiac arrest,” according to his family.

When Green was hired in 1989 to succeed Jack Elway, he became the first African-American to head a football program at Stanford and in what is now the Pac-12 Conference.

Green spent three seasons on The Farm, compiling a 16-18 record and taking the Cardinal to the 1991 Aloha Bowl in Honolulu, where it lost to Georgia Tech after an 8-3 regular season.

“He was a tough guy with a warm side,” Andy Geiger, the Stanford athletic director who hired Green, said by phone from his home in Washington state. “He was very highly regarded by Bill Walsh.”

A disciple of Walsh, Green had two stints as an assistant with the 49ers, both under the iconic San Francisco coach. He was the special teams coach in 1979, then spent three seasons from 1986-88 coaching the wide receivers. Between those two jobs, Green served as Stanford’s offensive coordinator in 1980 and was the head coach at Northwestern from 1981-85.

“He was my wide receiver coach for so many years and we stayed friends over the years also. So I’m real saddened by it,” Jerry Rice told reporters at the American Century Championship in Lake Tahoe. “He really did a lot for my career, because he was one of those coaches that never let me get complacent. … He was the type of coach that really influenced me throughout my career. He was more than a coach. He as almost like, you know, my best friend. Someone I could always depend on.”

After leading Stanford to its first bowl game in five years, Green left to become the second African-American head coach in the NFL’s modern era when he was hired by the Minnesota Vikings in 1992. He led the Vikings to two NFC Championship games during his 10-year career there. Green’s Vikings went 97-62 and went to the playoffs eight times.

“Dennis Green created an outstanding environment for his players and I was privileged to spend four great years under his guidance in Minnesota,” Raiders coach Jack Del Rio said in a statement. “He was a real trailblazer, and his impact on the game continues to live through the many successful coaches that he mentored.

“One of his phrases, or ‘Denny-isms’ as we call them, is ‘We’re going to plan our work and work our plan.’ I still use that ‘Denny-ism’ today. Coach Green is going to be missed dearly by everyone that was lucky enough to know him.”

Green also coached the Arizona Cardinals from 2004-06, leading them to a 16-32 mark. He finished his NFL career with a 113-94 record.

At Stanford, Green inherited a team that went 3-6-2 in its final season under Elway. The Cardinal was 3-8 in its first year under Green, then improved to 5-6 and 8-4.

His assistants included future Baltimore Ravens Super Bowl champion Brian Billick, Ron Turner, Tyrone Willingham and Willie Shaw, the father of current Stanford coach David Shaw.

“At Stanford, Coach Green created an environment of toughness, confidence and competitiveness that I was blessed to be a part of as a student-athlete,” said David Shaw, a backup receiver for the Cardinal under Green. “Though our staff, Coach Willingham’s and Coach (Jim) Harbaugh’s have all had success, Coach Green was the first to win at Stanford with the combination of a physical running game, a West Coast passing attack and an aggressive defense.”

In addition to Shaw, players on Green’s roster at Stanford included Tommy Vardell, Ed McCaffrey, John Lynch, Bob Whitfield and Cory Booker, now a U.S. Senator from New Jersey.

“I am deeply sorry to hear of the passing of my Stanford football coach & NFL coach Denny Green. My condolences are with all his loved ones,” Booker tweeted.

One of the more poignant tweets came from Robert Smith, the former Vikings running back who spent his entire eight-year career under Green.

“Rest in peace Denny. I lost my mother in April, I feel like I just lost father,” Smith wrote.

Green’s tenure at Stanford had its share of excitement.

The Cardinal went 3-0 against Cal, including a 38-21 victory over a sixth-ranked Bears team in 1991. Stanford also ended a 16-year losing streak against USC and in 1990 stunned top-ranked Notre Dame 36-31 in South Bend.

A story on gostanford.com recalled Green’s confidence in his team before that game. The coach ordered the bus driver to do a pregame victory lap around Notre Dame Stadium, and he told the Stanford players to soak it in.

“I got off the plane and smelled football,” Green said after the game, according to the story on the Stanford website. “Everything about the Midwest is football. It was great. The sirens of the police escort were blaring on the way to the game and all I could think was ‘Move over, here comes the goddam Stanford Cardinal.’ “