Chip Kelly, shown in December when he was coach of the San Francisco 49ers, attended spring practice at Navy on Monday. (Kevin C. Cox/Getty Images)

The Navy football team welcomed a special guest for spring practice this week, with Chip Kelly observing the Midshipmen on Monday as they worked primarily on situational drills such as goal-line management and two-minute offense.

The former head coach at the University of Oregon and of the Philadelphia Eagles and San Francisco 49ers of the NFL is a friend of the Navy program, according to Coach Ken Niumatalolo. “Obviously one of the best coaches in the game,” Niumatalolo said of Kelly, who was also scheduled to attend the final two spring practices in Annapolis on Wednesday and Friday. “For us to have an opportunity to be around him, learn from him, we’re just trying to soak in as much as we can.”

During Kelly’s four seasons as Oregon’s head coach, the Ducks overwhelmed opponents behind a no-huddle spread offense, appearing in a Bowl Championship Series bowl game each year, including the 2010 national championship. That season, Kelly was selected Associated Press national coach of the year after Oregon went 12-1, losing only to top-ranked Auburn in the BCS title game.

“Some of the things he did at Oregon revolutionized football,” Niumatalolo said. “Everybody’s doing no-huddle, one-word concepts. His offseason stuff, his up-tempo stuff, a lot of the things that he implemented, literally high school, college and pro guys are doing it. He’s definitely a trendsetter.”

Kelly’s offensive principles soon generated interest among NFL teams. Among the high-profile NFL coaches Kelly met with to discuss his offense that rolled up points at a dizzying rate was the Patriots’ Bill Belichick, whose father, Steve, served as an assistant coach at Navy from 1956 through ’89.

In January 2013, Kelly became coach of the Philadelphia Eagles, directing them to a 10-6 record and the NFC East Division title in his first of three years with the club. The Eagles had gone 4-12 in the previous season. But his final two seasons in the NFL yielded eight wins combined, along with some questionable personnel decisions.

After being dismissed from the Eagles in late 2015, Kelly reportedly had interest in Navy when Niumatalolo was exploring the vacancy at Brigham Young.

Kelly most recently was dismissed in January after one season with the 49ers. The 49ers finished 2-14, the second-worst record in the NFL. He remains in coaching limbo, although he has indicated he would consider all possibilities with regard to his next job.

“There’s not too many coaches who’ve been innovators like he has,” Niumatalolo said. “He’s a phenomenal coach and great person.”