Mark Geiger signals a call at a 2014 World Cup qualifier soccer match between Honduras and Panama in Tegucigalpa, Honduras. (Moises Castillo/AP)

It was 2:24 a.m. on a Tuesday in January when the e-mail from Zurich softly chimed into Mark Geiger’s phone. A former high school math teacher, Geiger is one of only nine salaried full-time professional soccer referees handling Major League Soccer matches, but the e-mail was by far the most important of his officiating career.

The message from FIFA, soccer’s international governing body, said he had been picked among 25 elite referees from around the globe to officiate at the 2014 World Cup in Brazil, which begins Thursday.

Geiger, 39, will be the only American tasked with overseeing games on the grass at the world’s biggest single-event sporting competition. No American referee has been invited to work as a “center,” or primary, ref at a World Cup since 2002.

“He’s one who feels he’s always right about everything, and he usually is,” said his brother, Steven Geiger. Other pro referees say he is good enough to become the first American official to make it out of the World Cup group stages as a center referee.

“I don’t think he’ll be making any mistakes,” said Michael Kennedy, a former FIFA-listed referee whose job at the New York-based Professional Referee Organization includes monitoring Mark Geiger’s performances in MLS, where Geiger has officiated for 11 seasons. “At the end of the day, he’s got that mentality and toughness and fitness to get in there, stay close to play and find the right angle to get it right.”

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A former MLS referee of the year, Geiger has the ability to consistently make correct calls under pressure. It helped him get to the 2012 Olympics in London, where he confidently issued a straight red card to a player from Spain during the opening game against Japan. He has been selected once by FIFA for an international final — the 2011 Under-20 World Cup championship match in Bogota, Colombia, between Brazil and Portugal, won by Brazil in extra time.

“Fate and opportunity and preparation have paved the way for him to shine at this tournament,” said Joe Romayo, a soccer-loving former math student of Geiger’s who now teaches history in New Jersey. “He’s got a chance to be the Howard Webb of the 2014 World Cup.” Webb is a prominent referee in England’s Premier League who also handled the 2010 World Cup final between Spain and the Netherlands.

Geiger doesn’t know about that. Too many variables, even for a recently retired Advanced Placement math teacher. But after waking up that January morning and reading the e-mail from FIFA, he knew one thing.

“Whether you’re from Italy or Spain or the U.S.,” he said, “to get the next game, you have to earn it.”

Dropping math to officiate

Geiger’s path to Brazil began in his home town of Beachwood, N.J., when he was 13 and needed some pocket money. Geiger started doing rec-league games on weekends, and still remembers his first game, when he incorrectly awarded a pair of goals he should have disallowed as offside.

“The assistant referee had his flag up for quite a long time” both times, Geiger said he was later told. “I remember completely ignoring my linesman and having to call back those two goals.”

Geiger continued learning as a part-time referee in high school and then as a student at Trenton State College, where he earned a teaching degree. He played soccer as a kid, sticking with it until high school, when he joined the track team.

As for math, Geiger said, “I was just good at it.” He was good at teaching, too. Before leaving his whiteboard behind last February to focus on his referee career, Geiger was chosen in 2009 for the prestigious Presidential Award for Excellence in Math and Science Teaching. He received the award at the White House, where he shook President Obama’s hand before returning to Beachwood, where he continues to live.

Geiger obtained his National Referee badge in 2003 while still employed at Lacey Township High School in Ocean County, N.J. He began refereeing MLS games a year later, part time. In 2008, Geiger was added to U.S. Soccer’s International Panel of Referees, making him eligible for higher-profile international matches and requiring more travel. Offered a full-time, salaried position with the Professional Referee Organization last year, he reluctantly decided to retire from teaching, aware of FIFA’s preference for officials with full-time referee jobs.

Geiger’s two assistant referees, Sean Hurd of Jacksonville, Fla., and Joe Fletcher, a Canadian, will accompany him in Brazil. The three have worked and traveled together for three years, forming a tight professional bond.

In a statement, FIFA said it based its decision on Geiger and the other World Cup referees “on their personality and their quality in football understanding by being able to read the game and the teams’ tactical approaches towards each game.” (Geiger and his assistants will only be eligible to officiate games outside the U.S. team’s group, which includes second-ranked Germany and fourth-ranked Portugal, as well as Ghana.)

Geiger resisted a reporter’s request to explain the qualities that enabled him and his partners to qualify for Brazil from the initial shortlisted pool of 52 referee trios.

When pressed about it though, Geiger said teaching math probably helped him make the final cut.

‘He’s confident, consistent’

If mathematics are about quantity, structure, space and change, so too are the dynamics on the soccer pitch, Geiger explained. Maintaining order and clarity in a classroom of gifted, confident students is not so different than fairly governing the lightning-fast interplay of 22 of the world’s most sublimely talented and craftiest soccer players.

“When I was in the classroom, it was 25 or 30 students each with a different learning style,” Geiger said. “On the soccer field you have 22 different players, each with different personalities. So it’s about recognizing what’s going to work with a particular player and then implementing that.” He added: “The situations that are in the grey areas, preventing players from taking that next step, communicating with them, managing them, working with them” is what a good referee brings to the game.  One of seven FIFA-listed center referees from the United States, over the past six years Geiger has traveled in Europe, Africa, Central and South America to oversee international matches. Along with the two Olympics games in 2012, the four matches he handled during the U-20 World Cup finals in Colombia, which culminated in his officiating the championship game, remain his most memorable. The U-20 final also marked the first time an American official refereed a major FIFA men’s tournament championship.

Last year, in what may have been his final exam by FIFA, Geiger and his team went to Morocco for FIFA’s Club World Cup, won by German juggernaut Bayern Munich. Geiger and his team handled the fifth-place match between an Egyptian and a Mexican club, and Geiger later served as the fourth official at the championship game. He and his assistants also handled four World Cup qualifiers.

So far, his biggest matches have been devoid of controversy or drama.

“It’s a statement that he’s doing great work and plying his trade in a professional manner,” said Kennedy, the referees manager at the Professional Referee Organization. “He’s confident, consistent, and constantly learning and wanting to do the best he can.”

Geiger, whose widow’s peak and dark eyes create an owlish, mildly sinister impression that comes in handy during games, shrugs off questions about whether he’ll come in for extra criticism or scrutiny at the World Cup because he is American, representing a country still struggling for the respect of the soccer-loving world.

“I hope they just look at us as referees, and that we all went through the same process to get there, and that we’re treated with respect,” Geiger said.