EGLIN AIR FORCE BASE, Fla. — When Glen Coffee left the University of Alabama a year early to play in the National Football League, it surprised many fans. He was coming off a strong junior season in which he rushed for 1,501 yards, but could have returned and worked toward a better draft position the following season.

Behind the scenes, the decision included far more turmoil than that. The running back had stopped enjoying football years before, even quitting a team in middle school before his mother intervened, he said. He found success at Alabama after a standout high school career, but still didn’t like the game and left the university because he thought an NFL paycheck might make playing more palatable, he said.

“I got to high school, and I played because my friends played, and then when I realized that I was good enough for college, at that point it was to get school paid for,” Coffee said. “And I still had a year left to play at ’Bama, but I didn’t come back because I didn’t want to play football anymore. So I figured if I got paid to play football, I would tolerate it. So I got to the NFL and I got the money, and it was mo’ money, mo’ problems, pretty much. And I found out it wasn’t for me.”

Coffee, 28, is now a specialist in the Army infantry after enlisting in 2013. He agreed to an interview here with The Washington Post while media were at Eglin for another assignment. He has rarely talked to the media since becoming a soldier.

Coffee quit football in April 2010 after playing just one professional season with the San Francisco 49ers. He told a journalist afterward that he found Christ while in college and no longer considered professional football to be his dream, and then returned to his hometown area on the Florida Panhandle. He told another writer that he regretted leaving college early.

Coffee enlisted with plans to join the Special Forces. That dream hasn’t worked out, but he is now a paratrooper assigned to Army Ranger School, which trains elite soldiers and has a third and final phase of training here in the swamps of Florida. Coffee, who grew up in nearby Fort Walton Beach, requested the position, and now works for 6th Ranger Training Battalion.

Coffee said he had “no clue” what he wanted to do when he left the NFL. But he felt drawn to looking for a higher calling. He spent a couple years mostly in Florida with his young daughter after leaving the 49ers, a stay-at-home father of sorts.

“I just felt like the league and that path wasn’t for me,” he said. “I just knew that I didn’t want to waste, for me, my younger years doing something that I didn’t want to do. That was kind of my viewpoint on the situation.”

Coffee said he debated enlisting for about a year before signing the paperwork. There were two reasons he went for it, he said. One was for himself, he said: Pursuing military service on an elite level had a “wow factor” like playing in the NFL did. The other was for others and his country.

“Not everyone can serve in combat arms, and not everyone can serve in a Special Operations capacity,” he said. “So that’s why I joined. I felt like I was able to do it. Physically and mentally, because there is a mental aspect to it, too.”

Although not in Special Operations, Coffee serves in the waterborne operations section of Ranger School. He is asked regularly if he wants to attend Ranger School himself. The grueling leadership course is a minimum of 61 days long, with minimal sleep and food and stints at Fort Benning, Ga., and the mountains of northern Georgia before arriving in the swamps of Eglin Air Force Base.

“That’s one of those things I ask myself right now, as a matter of fact,” Coffee said of attending the course. “Am I thinking about that because I want to do it out of pride, or because it would actually better me as a person? So, I’m debating that right now. I have to ask myself, why would I want to go?”

Coffee’s section leader, Sgt. 1st. Class Joshua Sullivan, said Coffee has shown himself to be quiet, humble and “squared away,” one of the biggest compliments one soldier can give another. It’s not uncommon for inexperienced soldiers to have doubts about attending Ranger School, but many of them with Coffee’s drive eventually gravitate toward the challenge, Sullivan said.

“The first long-distance run I ever took him on, he stayed with me the whole time,” Sullivan said. “I have guys who have been doing that run for a full year, and some of them fell out.”

Sullivan added that the other soldiers in Coffee’s section know about his past playing in the NFL, and teased him about him recently when he dropped a pass in a flag football game held on the installation. But he showed his tenacity and athleticism by improving his swimming to the point where he was no longer considered weak at it.

“He just jumped in the deep end, and figured it out,” Sullivan said.

Coffee said the kind of athleticism necessary to be a soldier is completely different than playing football. He didn’t run his first full mile until he was 24, after retiring from the NFL, he said.

“My cardio and endurance is definitely a lot better right now,” Coffee said. “Because in football, you’re not really in shape. People think you’re in shape, but you’re really not. Not like that.”

Coffee isn’t sure if he’ll stay in the military for at least 20 years and earn a retirement. It seems like a long way away, just like it does for many other relatively inexperienced soldiers.

“I would never say never, but as of right now I have so much I want to do,” Coffee said. “So my first option is not to make this a career. But, you get to a certain age in life, and you realize that life doesn’t always happen as you plan, so we’ll see. We’ll see what happens.”