Jack Harrison was living the dream of millions of English children, playing for Manchester United’s youth academy, when his mother convinced him to come to America for an education to fall back on in case soccer didn’t pan out. It turns out it may have been the best decision for the teen’s soccer career, as well.

On a star-studded New York City FC roster featuring MLS-leading scorer David Villa and icons Frank Lampard and Andrea Pirlo, Harrison has been the biggest difference-maker. Lampard called his 19-year-old protégé a “revelation,” as the Rookie-of-the-Year candidate has taken NYCFC’s attack to a new level.

“When [the ball] does come, you need to be a bit special, and he’s been a revelation for us in turning the corner and winning these last five out of six games because he’s given us a real outlet of speed and ability on the ball,’’ Lampard said.

“Jack’s been great since he came into the team. For a player his age to come in with such confidence and ability to play so well, he’s given us an edge on that right wing. He’s a huge part of the last few performances and he’s got a huge future. With Jack doing his thing on the wing and the rest of us coming in behind, adding goals, creating chances we can be a team that can actually win a championship.”

For the first time, NYCFC actually look like a contender, atop the Eastern Conference (33 points) and the highest-scoring team in the league. The best stretch in their history has come since Harrison entered the lineup seven games ago, scoring three goals and assisting two more to see his team vault from fourth place to the top of the table.

“He’s got a natural ability on the ball,” Lampard said. “Some players just know when to pass, when to dribble and they have a natural ability to skip past people. On top of that, he’s got a lot of humility and he’s a really good kid. He wants to learn, wants to work hard in the week, he’s not ahead of himself and I don’t think he ever will be because he’s so good. He’s a real weapon for us now and he’s got everything he wants in front of him.

“He’s got a good family and a good head on him, and I know that well because I worked side-by-side with him [when both were injured]. Being English boys, I tried to take him under my wing. … At 18 I’ve seen a lot of good players with ability and Jack’s the latest. He’s up there with as good ability as I’ve seen at that age.”

That family is his mother, Debbie, who started her only child on this American adventure.

“My mom worked so much, from a young age I’ve always been able to figure things out for myself. I like being away from home,’’ Harrison told The Post. “To come to America, be in a dormitory [was great]. I’m an only child, I wanted a brother to play with.”

Now, he’s helped a team full of older brothers into first place.

Born in Stoke-on-Trent and raised in Bolton in northwest England, Harrison spent seven years in the Manchester United academy that produced stars Bobby Charlton, George Best, David Beckham and Ryan Giggs. Of the current Manchester United squad, Marcus Rashford was a year below him, Cameron Borthwick-Jackson in his group and James Wilson just a year older.

Yet, for all the names that make it out of the academies, hundreds more are discarded and never heard from. That’s why Debbie Harrison — a single mother who works as a personal assistant in a law firm — hedged her bets, sending her only child across the Atlantic to the Berkshire School in Sheffield, Mass., at just 14 years old.

“In case there’s an injury she wanted a backup plan. When I was 13, 14, she started introducing the idea of going to America to concentrate on the academic side. At first I was apprehensive; every kid in the academy is just thinking about going to Man United. It’s tunnel vision,’’ said Harrison, who uses Skype and messages his mother daily.

“My mum was working [on this] when I was around 11 or 12, reaching out to people. She’s done everything, she’s done all the research. Without her, I wouldn’t be where I am today. I’m really grateful. … It was a tough decision to leave the academy, but everything worked out for the best.”

The calculated gamble paid off, with Harrison the Gatorade National Player of the Year at Berkshire and then the only freshman to make an All-America team last year at Wake Forest. But it was his exploits on another team that landed him at NYCFC: The Manhattan Soccer Club.

While staying with a high school teammate at his Upper West Side home for three summers, Harrison starred for the Manhattan Soccer Club, NYCFC’s youth affiliate. When NYCFC put in a homegrown claim that was denied, they traded up to use the top overall pick on the youngest player in the 2016 draft. It turned out to be a good call, despite a fractured pelvic bone that cost him three months.

“That was really humbling to [find] out how much they wanted me,’’ Harrison said.

“He’s a great kid,’’ said NYCFC director of football operations Claudio Reyna. “He’s been in the New York area for the last three years at Manhattan Soccer Club playing for one of our youth affiliates. It’s a great story, but more than anything we got a fantastic kid and an excellent player.”

NYCFC was 4-4-6 with a minus-6 goal differential when Harrison entered the lineup, but they’re 5-2-0 since with a plus-5 differential. His pace on the counter adds a speed element sorely lacking in a plodding, older side with Lampard (38) and Pirlo (37).

“I like going at my defender 1v1,’’ Harrison said. “I like cutting in on my left foot and taking a shot.”

Like when he crossed Cameroon national team defender Ambroise Oyongo three times and beat him for a curling left-footed goal in last weekend’s win at Montreal.

Now, instead of having to build every attack slowly, methodically and inexorably, NYCFC can hold the ball deeper and relieve pressure with a ball to Harrison in transition.

“I just keep reminding myself being able to do this, play soccer as a job, is pretty special. Not many people are able to do their hobby as a job,’’ Harrison said. “It’s just enjoyable.”

Harrison has enjoyed it so much he may want to stay permanently.

“I’m in final stage of green card,” he said. “I think it’ll be couple more months.

Harrison has never played for the England at any level and would be open to apply for citizenship here, perhaps to join the U.S. National Team in the future.

“Whoever would come first,” he said.