Long Island junior Jack Kennedy practices Botic van de Zandschulp...

Long Island junior Jack Kennedy practices Botic van de Zandschulp under the watchful eye of coach Noah Rubin during the U.S. Open at the Billie Jean King National Tennis Center on Friday. Credit: Errol Anderson

When Long Island junior Jack Kennedy took Court 15 at the U.S. Open on Friday for a practice session with Botic van de Zandschulp, the Dutchman who’d just the night before upset Carlos Alcaraz at Arthur Ashe Stadium, few fans watched. But more gathered as the two began to hit, their easy rhythm building into something ferocious.

Kennedy, 16, of Huntington, is scheduled to make his U.S. Open junior debut Monday against Mees Rottgering of the Netherlands, the No. 4 seed.  He is midstream in the most momentous year yet of his tennis career.

The week before van de Zandschulp asked him to practice, Kennedy played the Open men’s qualifying tournament in front of hundreds of fans screaming “Jack!” at the National Tennis Center, losing to Maximilian Marterer, a German veteran ranked No. 100 in the world, in the first round. The match earned Kennedy his first tennis paycheck: $25,000. He kept only $10,000, abiding by an NCAA rule to preserve his college eligibility.

Kennedy’s junior ranking of 32 in the world would not normally entitle him to a spot in the Open qualifiers, but he’d gained entry by reaching the finals of the United States Tennis Association Boys 18s National Championships in early August. Before that, he’d played junior draws at Milan, the French Open and Wimbledon. In one five-week span this year, he won four high-level international tournaments in a row.

Competing at the Open, Kennedy said in an interview after his practice, “was “unreal. Just to play in front of that crowd — I’ve never experienced anything like that.” Usually, he said, he hates to lose, but this loss had boosted his confidence. He’d been impressed by his opponent, who “didn’t get defeated by the crowd, his shot quality was very high. He consistently hit the same ball, over and over again.”

Kennedy lost in straight sets but there were deuce games and break opportunities. “I can hang in with that guy,” Kennedy said.

Kennedy’s father, Bryan Kennedy, who works at a lighting manufacturer, said neither he nor his wife, Jeannie, a school guidance counselor, were elite athletes, but that Jack had shown unusual hand-eye coordination as a baby. He was 2 1/2 when he got his first racket, which he used to hit Nerf balls with his dad in the family’s living room. Later he played at Huntington Indoor Tennis and on the courts at Huntington High School.

When he was 6, he attended an open tryout at the John McEnroe Tennis Academy at one of the Sportime tennis clubs, meeting high performance coach Greg Lumpkin, who still coaches him at Robbie Wagner Tournament Training Center in Glen Head. Scholarships from the academies and USTA were essential, Bryan Kennedy said. “We’re probably able to afford one day a week, and unfortunately, that’s not enough,” he said.

Kennedy trains daily, four to six hours a day. He travels to tournaments across this hemisphere and in Europe. After eighth grade, he left St. Patrick’s School in Huntington for an online school that accommodates his tennis schedule. He is now a rising junior. Bryan Kennedy said that about 50 college coaches have contacted the family.

What happens next week and at tournaments in the next two years will help determine whether Kennedy goes straight to college or the pro tour.

“Always, since a very young age, I’ve wanted to go pro,” Kennedy said, though he said he would not make the jump without achieving good results in the futures and Challenger events that function like professional tennis’ minor leagues.

Former touring pro Noah Rubin, who reached a career high of world No. 125 before retiring and is helping coach Kennedy, said the junior had some advantages over his peers, aside from astonishing foot speed.

“He’s got an amazing, super down to earth family” in a sport where that is anything but a given. Kennedy also has perspective, Rubin said. “A lot of things will come naturally to him because he understands that there’s a process ... As he sees the levels, almost without coaching, he’s going to get better on his own.”

Wagner said his pupil was one of the hardest-working players he’d seen. Kennedy stands about 5-6’, shorter than most of the men at the top of the game, and does not yet have a serve that will win many free points at the professional levels Wagner said. Without it, “To grind for points, at some point, that wears on you.”

At practice, Kennedy and van de Zandschulp hit down the middle, then crosscourt with heavy topspin forehands, crosscourt the other way with flat skidding backhands. The practice lasted an hour.

“He’s a nice ball striker,” van de Zandschulp said later. “You can easily play some good rallies with him.”

Kennedy came off the court and said he liked his chances. “I’m going to enjoy this moment and play at the highest level I’m capable of.”

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