Over the past two decades, George Mason University slowly shed its reputation as little more than a decent commuter campus and evolved into a nationally respected academic institution with an enrollment that tops 32,500 and an endowment that swelled to $100 million.

The school’s coming-out party was punctuated during the 2006 NCAA men’s basketball tournament when the low-seeded Patriots upset more established powerhouses en route to the program’s first-ever Final Four appearance. On a national stage, the Fairfax school’s scrappy team suggested that anything was possible.

Except, perhaps, keeping the high-profile coach who made it happen and became synonymous with George Mason’s rise.

On Friday, Coach Jim Larranaga, 61, announced he was leaving the school after 14 seasons to take a job at the University of Miami that reportedly will pay him more than twice the $525,000 base salary he earned at GMU. Coming a month after the announced retirement of longtime school president Alan G. Merten, the other man credited with lifting Mason’s national stature, Larranaga’s departure was a blow to a campus that had begun to think of itself as a final destination for top talent, not a waystation to bigger and better things.

Now its rank in the hyper-competitive world of big-time college basketball is dependent upon whomever the university’s leaders can woo to take his place — and doesn’t seem quite so assured. How all of this affects George Mason’s steady rise among up-and-coming universities awaits a season of a different sort next fall: application season.

“I never thought he would leave; I thought he would retire here at Mason,” said Sean Gagnon, 24, who graduated last year with a degree in environmental science and bought basketball season tickets last year. “He had turned down other jobs, even with his alma mater. To see him leave is heartbreaking.”

At a news conference Friday, GMU Athletic Director Tom O’Connor praised Larranaga and said the athletic department will miss him but supports his decision to leave. He stressed that Larranaga had made the basketball program a hot commodity for recruits and promised to find a top-notch replacement who can hopefully keep the Patriots among the elite in the Colonial Athletic Association.

But, perhaps fearful of taking too much blame for losing the coach, O’Connor played down Larranaga’s and the basketball team’s broader impact on campus.

“What happened in the ’06 season gave us the opportunity to tell the great story of George Mason,” he said. “But we have to put everything in perspective. Many times, people say that intercollegiate athletics . . . [is] the front door [to a university]. It’s not the front door. It’s the side door. In the department store of higher education, we’re the toys and games department. When you think of it, when you go into the side door of a house, it’s usually the family room or the kitchen, where people are smiling. That’s how I look at it. It gave us great visibility for the basketball program, but it didn’t come in the sense that it became more important than the university as a whole.”

Still, Larranaga became perhaps the most recognizable face of the university. He paired with the National Geographic Society to create a globe-themed basketball, addressed local and national business groups and became a regular on sports talk shows. And whereas the school’s image was previously associated with Gunston – a goofy green mascot – and an obscure founding father, now it was associated with Larranaga.

On a popular Internet message board dedicated to Patriots basketball, fans griped about GMU’s inability to keep the coach, comparing it to Virginia Commonwealth University’s recent re-signing of Coach Shaka Smart after he led that school to a similarly unlikely Final Four berth this month.

“It is amazing to me that VCU could come up with $1.2 [million] for Smart and GMU couldn’t come close to matching UM,” one commenter wrote. “I’m going with what a lot of the Mason fans are saying. There must be a lack of commitment from the top. That is really sad if true.”

On campus, P.T. Mulquin, a sophomore tennis player who is president of the student-athlete advisory council, rued Larranaga’s departure, noting that the coach had built a program that could be a preseason Top 25 team next year with several stars returning and two good recruits coming aboard. Why would he leave for a middle-of-the-pack Atlantic Coast Conference team? Mulquin wondered aloud.

“It’s not about finding a niche. He had that here,” Mulquin said. “It must be about the money.”

During 14 seasons, Larranaga led the Patriots to three conference championships, five NCAA tournament berths and a 273-164 overall record.

The impact of a successful big-time collegiate sports program can be at once easy and difficult to assess. There are the quantifiable extra dollars earned from TV contracts and postseason games, but there is also the enormous free advertising for the school in the mass media and the potential increase in enrollment that can follow.

A year after the 2006 tournament run — which ended when the Patriots lost to eventual champion Florida, 73-58, in Indianapolis — Robert Baker, a GMU associate professor, examined the effect on the school. He found that out-of-state applicants increased by 40 percent in the 2007-08 academic year compared with two years before, while the total number of freshman applicants rose 22 percent.

Bookstore sales were higher in March 2006 than the entire previous year; donations to the Patriot Club, an athletic department booster program, increased by 52 percent; and basketball season ticket sales doubled, Baker found in his report.

Baker, who works in the Center for Recreation and Tourism Research and Policy, acknowledged that Mason had made substantial academic progress before the 2006 season that contributed to the enrollment gains.

But, he concluded, “Mason’s 2006 Final Four run made the team an instant fan favorite and the university a household name.”

“It’s unbelievable,” said Bill Courtney, a Fairfax County native who was part of Larranaga’s first coaching staff and is now the head coach at Cornell. “People forget what that place was like when we got there. People forget. It was a different world then, a different school.

“When we first got there and we called recruits, it was always ‘Where are you from? James Mason? George Madison?’ People didn’t know,” Courtney continued. “Now, people don’t make that mistake.”