When we hear “Georgetown basketball fraternity,” most of us go straight to Ewing, Mutombo, Mourning. We think Big John’s scowling old heads and J.T. III’s new-school scorers and passers. Somewhere in between is Iverson; then Harrington and Sweetney; Hibbert and Green; and Monroe. Until all those faces and others coalesce into one black-and-white framed photo behind a glass case in musty McDonough Gym, under a heading that reads, “Hoya Family.”

Except in Jeff Green’s mind. He had a hard time seeing himself in that photo.

Crazy, no, he hasn’t felt completely part of that family since he left the Hilltop for the NBA five years ago. “Something always felt missing,” he said Thursday as he climbed a steep metal ladder inside McDonough. Atop a perch where he could see Georgetown President John J. DeGioia giving a speech at senior convocation, Green looked longingly at the students in caps and gowns.

“Finally,” he said.

On Saturday morning, five years after he walked across a Manhattan stage as an NBA lottery pick, Green will traipse across a stage in his own cap and gown. Four years of summer school later — of five-day-a-week, two-hour lectures, papers and discussions — the No. 5 pick in the 2007 draft will be handed a diploma, his degree in English with a minor in theology.

“It’s one of the proudest moments of my life, you know, first person to graduate from college in my family — first person, really, from my neighborhood that I know of that got a four-year college degree,” Green said. “I know some people I grew up with that went to junior college, but I can’t remember anyone who got a four-year degree.

“I might cry. I might smile. I just know I’m going to feel proud I did it — one of the hardest things I ever did.”

Some of us, including many of Green’s ballplaying peers, might ask an obvious question: Why? Why return to college for a degree that could not possibly financially benefit you the way your current profession has?

Imagine signing a multimillion dollar contract at 21, which ostensibly would make you financially secure for life. Then picture the large-living existence of the NBA: Ritz-Carlton and Four Seasons’ maids make your bed, the team secretary makes your travel plans, you never have to fly coach for work, or even print out your boarding pass the night before.

“The obvious answer is the average NBA career only lasts four years and it’s nice to have a backup plan. But for me , it was more than that,” Green said. “A lot of it was watching Jonathan Wallace and Tyler Crawford and Pat Ewing [Jr.] and all the guys I was close with when they graduated. It really hurt that I didn’t get my degree. I decided I needed to go back and do it.

“Honestly, there are times when I regretted not staying. I’d see the Davidson game [which Georgetown lost in the second round of the 2008 NCAA tournament] and think, ‘Man, if I was there, we wouldn’t [have] lost to them,’ or something like that. But most of the time, it was just that I didn’t get to have a graduation day with my closest friends. I was actually lonely that first year, when I got drafted by Boston and traded to Seattle. That was all the way across the country. I’d be sitting in apartment, in some city I didn’t know, thinking, ‘Why did I leave?’ ”

So he came back — sort of.

When all of his NBA teammates headed to more exotic locales each offseason, Green came home and hit the books. The first week of each five-week summer semester was the worst, he said. “I would just be sitting there, thinking, ‘Why don’t I just go to L.A.?’ Or anywhere else but a lecture hall or classroom.”

Also, Green turns 26 in August. He knows that still sounds young, but it feels old when the kid next to you in class is 19 or 20, and keeps bugging you every minute for inside information on the Boston Celtics.

“It was last summer, a kid from Boston who knew who I was,” Green recalled. “He did the old, ‘What’s Kevin Garnett really like?’ And he wouldn’t stop. After a while, it wasn’t so bad. But I didn’t really know him, and I just wanted to pass the class.”

He spent many evenings at Thomas Sweet’s ice cream shop at the corner of Wisconsin and P streets. At 6 feet 9, he would occasionally get a “Didn’t you play at Georgetown?” Worse, he felt the judgmental glances he thought meant one thing: Can’t Jeff Green move on with his life? He’s still hanging around Georgetown years after he left school?

“I almost wanted to tell people, ‘Dude, I’m not that guy. I don’t want to be that guy. I’m actually still taking classes, trying to graduate,’ ” he recalled. “A lot of the experience was humbling. But, mostly, I gotta say: it was rewarding. Really rewarding. I’m not hating on guys that never go back to school or leave school early, but for me, it was an experience that made me who I am in many ways.”

See, when you grow up in a part of Hyattsville where you don’t meet many people who don’t look like you and think like you, college life opened his eyes in ways he never imagined.

“Even recently, I was taking a class on biblical passages where we would take, for instance, the Adam and Eve story and dissect it from many different perspectives,” Green said. “And part of me is thinking, ‘Wait, I didn’t grow up questioning anything about the Gospel.’ But we’re having these discussions among small classes, and they’re actually thought-provoking, making me think about things.” He laughs. “And I know if I don’t participate, I am not passing that class.”

The impressive part about Green walking across a stage in cap and gown Saturday is his commitment to getting his degree long before the bad news late last year.

On December 10, he signed a one-year, $9 million deal with Boston. But a week later, he had an aortic aneurysm diagnosed, which forced him to miss the 2011-12 season. Because of the surgery he failed his physical, which essentially revoked the Celtics’ qualifying offer. Following season-ending surgery, Green voiced his desire to return, and if everything goes well during workouts for teams, he’ll emerge as one of the league’s top free agents in July.

Even after his career resumes, he said he would have felt empty without the diploma. “I know that sounds weird, but you had to see how happy my friends looked when they graduated, what it meant,” Green said.

He had all the hoop credentials: Big East player of the year, the best player on a 2007 Final Four team that represented the school’s return to college basketball prominence. But he didn’t have the piece of paper that he wanted.

“Jon [Wallace] helped me a lot, encouraging me to do it,” he said. “It wasn’t easy. I dedicated four years of summer to school. This will be the first summer since I left I can actually relax and not go back to class. But I got my degree.

“When I think about how breathtaking and speechless I’m going to be — I still don’t know whether I’m going to cry or smile — I think I finally feel like a part of that family. Like I finally did what I came here to do when I signed my scholarship. Does that make sense?”

Perfect sense.

For Mike Wise’s previous columns, visit washingtonpost.com/wise.