On a typical workday, Nataly Arias is behind a desk in a four-story office building in Manassas recruiting for a government-contracting firm run by her aunt. It’s been a steady job since graduating from the University of Maryland.

Every so often, though, Arias must exhaust her vacation and sick-day balances and, when necessary, request unpaid leave in order to fulfill her other assignment: playing for Colombia’s national soccer team.

“I have the best of both worlds. I have a real job and I can compete in the greatest women’s competitions,” the right-side defender said by phone last week from the Swiss Alps, where Colombia was making final preparations for the Olympics.

Arias, 26, is a Northern Virginia native. Mentored by her father, she played for elite youth clubs and starred at Bishop O’Connell High School in Arlington. She capped her career in 2003 with a 30-goal season, all-America honors, The Post’s All-Met player of the year award and a scholarship to play for the Terrapins.

Arias never went beyond the youth system in the U.S. national program, a pioneer in women’s soccer that boasts a deep player pool and an elite senior roster. Through family roots, however, she has earned regular call-ups to the nascent Colombian program.

Arias played every minute at the Women’s World Cup last summer in Germany and the Pan Am Games last fall in Mexico.

Beginning next week, she and Colombia will confront a daunting group in their first Olympic appearance. Ranked No. 28 in the world, Las Cafeteras (essentially translated as the Coffee Machines) will need at least one victory and a tie against eighth-ranked North Korea, top-ranked United States and sixth-rated France in order to remain in contention for a quarterfinal berth.

Like most South American countries, where men’s soccer dominates conversation and resources, Colombia is decades behind programs in North America, Europe and Asia. Progress is measured in appearances in world events, not necessarily in results. Not yet, anyway.

“We know what we’re up against and we welcome the challenge,” Arias said. “The Olympics are another step in our growth.”

Two other American-born players are on the roster: forward Melissa Ortiz (Lynn University in Florida) and midfielder Ana-Maria Montoya (Arizona).

With U.S. defender Ali Krieger (Forest Park High) sidelined by a knee injury, Arias is the only female player from Washington’s vast youth structure to make an Olympic soccer roster.

After graduating from Maryland, Arias thought her competitive soccer days were over. She was cut by the Washington Freedom, which lasted two years in defunct Women’s Professional Soccer. With full-time work beckoning, pursuit of a semipro career in Europe wasn’t practical.

Her father, Fernando, an area youth coach for 17 years, thought she still had plenty to contribute. On his daughter’s behalf, he reached out to Venezuela, his birthplace. “They weren’t very interested,” said Fernando, who runs a furniture upholstery business in Woodbridge.

Colombia’s coach, however, was intrigued.

“I told him all about Nataly,” said Arias’s mother, Gladys, who was born in Colombia and moved to the United States as a child. “He responded, ‘Can she be here in four days?’ ”

Said Nataly: “I thought it might be my last chance to keep playing. I had to go.”

Arias earned a roster spot before the South American championship in late 2010 in Ecuador, where Colombia finished second to Brazil and qualified for the first time for both the World Cup and Olympics.

Aside from the on-field challenges, Arias encountered a cultural transition. Her parents mixed Spanish and English at home, but most of her communication at school and with friends was in English.

“I understood Spanish better than I spoke it,” she said. With help from her teammates, “I had to learn it again.” The Colombians call her “Gringa,” which, in this case, is an endearing term.

Balancing her American and Colombian allegiances, Arias said: “I grew up in a [U.S.] system that helped me develop. Watching the U.S. stars, they were my role models. But I feel a lot of pride being able to play for Colombia because it’s part of my family. I’m very lucky to be a dual citizen.”

Playing for Colombia has allowed Arias to connect with relatives in the village of Rionegro, her mother’s birthplace, and in Bucaramanga, the nation’s sixth-largest city.

Leading to the Olympics, Arias considered joining a U.S. club to maintain fitness and form. But work conflicts and Colombian duty pushed her, instead, to a personal trainer three days a week and workouts with her father.

“She’s taken a long road,” he said, “but she has gotten there.”

The Olympics have forced her to take a prolonged leave from DP Technology Services, which has contracts with military branches worldwide. Arias’s aunt, Darla Portillo, is president and chief executive, while Nataly’s mother is senior human resources manager.

When Colombia opens play next Wednesday against North Korea in Glasgow, family, friends and co-workers in Alexandria and Arlington, College Park and Manassas, Rionegro and Bucaramanga will tune in.

And when the Olympics end and her daughter returns, “She will probably take a few days off,” Gladys said with a laugh, “and then back to work, ASAP.”