PORT ST. LUCIE — Zac Herold recalls a class assignment in fifth grade in which he was asked to write down what he wanted to be when he grew up.

The now 17-year-old Port St. Lucie native scribbled, “professional soccer player,” and his teacher told him to be more realistic and think of something else.

So, Herold jotted down, “soccer legend,” and his teacher could only laugh at his playful stubbornness.

A day before the MLS SuperDraft, Herold already has sealed at least his initial dream.

He recently signed as a Generation adidas player, which makes him eligible for Thursday’s draft and guarantees him placement with a professional team. Herold has been predicted to go as high as the early second round as a defender.

“I saw (my old teacher) a couple of months ago, and she said, ‘Your dreams are finally coming true,’ so that was nice,” Herold said. “I do believe my dream is coming true, but at the same time, now I have to start all over.

“I have to prove myself on a new level. I’m a young player and I am just coming in a 17-year-old, trying to play with guys who are much more experienced and probably have no idea who I am.”

Herold has been playing soccer since he was 5 years old, but it wasn’t until six years later that his extracurricular focus turned completely to the sport.

He made the varsity team at Lincoln Park in sixth grade and his career took off from there.

Former LPA Greyhounds soccer coach Chuck Stewart is not surprised to hear of Herold’s turning pro.

“When I had him, physically, he wasn’t there — you could tell he was a sixth or seventh grader — but technically and athletically, the ability was there,” Stewart recalled. “He had all the moves and touches, a great mind and understanding of the game, and he was a great teammate.

“You could just tell he had it. As an ex-pro athlete myself, you can tell the kids that just have it. He certainly stood out.”

At the age of 13, Herold entered the Olympic Development Program, was named captain of the state ODP team and went on to play for the regional squad, as well, before earning a tryout for the national team.

Herold played every game with the U-14 and U-15 men’s national teams, and in the fall of 2007, after his freshman year, he enrolled in the U.S. Soccer Residency Program, an intensive training program in Bradenton.

Herold spent two years in the program, while taking classes at a private school that enabled him to graduate a semester early, but it was a rigorous process that took its toll.

“My first year was difficult,” Herold said. “I wasn’t doing well, I wasn’t playing as much, and I called my mom crying a lot. My coaches told me they were going to send me home if I didn’t start doing better. They saw it in me, but I just wasn’t producing.

“That triggered something in me, and I wanted to show them I could play.”

In the end, Herold proved his coaches right.

He worked his way to a starting role on the U-17 men’s national team that made it to the Round of 16 at the 2009 FIFA World Cup in Nigeria this past fall and was the anchor of the defense.

Already committed to play at the University of South Florida, Herold decided shortly after the World Cup he instead wanted to play professionally right away. He attended a tryout in Germany and drew an offer from FC Colon, but declined in order to stay stateside.

“The development would be better in Germany because soccer over there is just so much better, but being only 17, I don’t feel like I am ready to go to Germany, learn a new language and adapt to a new environment,” Herold said. “My head just wouldn’t be in it. I felt like I would be more comfortable here.”

Once soccer officials in the United States got wind he had decided to turn pro, MLS quickly jumped on him. He became one of 12 Generation adidas players at the beginning of this month and had a chance to improve his stock for the draft while playing in the adidas MLS Player Combine this past weekend.

He will travel to Pennsylvania for the draft on Thursday.

The road ahead has plenty of challenges, but Herold looks forward to the next phase of his career.

“It’s a lot of work and sometimes I get sore and tired and frustrated when I have bad games, but I will always have a love for the game,” he said. “Even living away from home, not living the normal high school life, being away from friends and family, I would still do it over again, 100 percent.”