Richard Pitino stared in awe at the hundreds of fans lining the hallway outside of the St. Raymond locker room after Isaiah Washington’s final high school basketball game.

Kids, teenagers, adults — all waiting for the new Prince of New York City basketball to emerge. Some fans were lucky enough to get their hands on purple “Just Jelly” custom T-shirts, honoring the nickname for the flashy finger-roll layup he has perfected, given away for Washington to sign. It was Senior Day, likely their last chance to see the celebrity point guard in the Bronx before he left for the University of Minnesota.

Unlike any Gophers recruit before him — perhaps in any sport — Washington has arrived in Minneapolis this summer with the fame and fanfare of a social-media superstar. And less than four months before his expected Gophers debut, St. Raymond’s all-time leading scorer is driving the already substantial buzz around his style and abilities even higher with riveting summer-league play.

In front of larger-than-usual summer crowds at DeLaSalle High School last month, Washington quickly lived up to the hype in his local debut. He scored 25 points in each of his first two Twin Cities Pro-Am games against college and pro players. A few hours before his 19th birthday on Thursday, Washington celebrated with 32 in his latest Pro-Am game.

Home Team Hoops

But back in March, Pitino only had heard about the “Jelly Fam” movement — or #jellyfam in today’s hashtag lingo. The Gophers coach didn’t truly get a taste of the internet-fueled frenzy until wading through a mob scene in the back of that crowded, dimly lit gym.

“I asked the coaches, ‘What is this for?’ ” Pitino said. “They said, ‘They’re all waiting for Isaiah.’

“They had T-shirt giveaways. Nike made up T-shirts about it. Everyone knows who he is. When I go recruiting, I have a Minnesota shirt on. And I’ll have kids say, ‘Jelly! You’ve got Isaiah Washington coming!’ It’s really an unbelievable phenomenon. Isaiah deserves a lot of credit for the creativity part of it.”

Twitter and Instagram might as well have created the grape emoji for Washington, whose name is rarely mentioned without it. The Jelly Fam co-founder hopes to have Williams Arena chanting “Jel-ly” this winter as the freshman drives for another finger roll.

“I didn’t know it was going to happen so soon,” Washington said earlier this year about his popularity. “I thought if I made it to the NBA, I’d have all these followers on Facebook and Instagram, stuff like that. It happening so early is a surprise.”

Highlight videos of Washington toying with defenders, using crossover, between-the-legs and spin-dribble moves, before a jump shot or jelly layup have hundreds of thousands of views on YouTube. Over 280,000 people follow his Instagram account; 26,000 more on Twitter.

“You watch him play and young kids say, ‘I can do that, too,’ ” Pitino said of Washington’s finger roll. “It’s an awesome marketing thing that he’s put together. Little kids throughout New York City love it. I’m excited about taking that to the next step.”

Prince of New York

An independent film crew followed Washington his senior year at St. Raymond for a documentary on his rise from little-known prospect to New York’s Mr. Basketball.

Roosevelt Byers, the coach and director at the Dunlevy Milbank Children’s Center in Harlem, remembers a scrawny 10-year-old ballhandling whiz from the nearby Lincoln Park projects.

“He has a training method where he cuts off half of the lights in the gym and he shoots in the dark,” Byers said. “Right in front of our eyes he developed. Isaiah was in here every day.”

In the eighth grade, Washington started hearing “Jelly” yelled out from Milbank employee Anwar Hannon. Washington adds a slight delay and extra, lightning-fast flick at the end of the finger roll — perhaps Hannon saw it as a sugary add-on.

Washington and his friend Ja’Quaye James liked the nickname so much they created Jelly Fam for their friends and fans, which gained a following after they posted the slogan on Instagram. The original Jelly Fam group of seven includes Jahvon Quinerly of New Jersey, one of the hottest recruits in the country.

With local NBA and college teams struggling, Washington’s group came at the right time to snatch up starving New York hoops fans.

Cleveland Cavaliers guard and New Jersey native Kyrie Irving had limited-edition Jelly Fam-inspired shoes made, making it an even bigger name. New York Knicks star Carmelo Anthony showed up to watch Washington play.

“Jelly is a finger roll,” Washington told Slam Magazine earlier this year. “We just add our own spice or sweetness to it. The initiation into Jelly Fam, you have to do three Jellys on somebody in one game. Once you do that you’re automatically in. But one of us has to be at the game. Or you have to have footage of it. We just want to be an example for kids growing up. Come play basketball and stay off the streets and join a social group.”

Pitino calls Washington a throwback New York City point guard, comparing his showmanship to legends such as Kenny Anderson, Sebastian Telfair and Stephon Marbury. Byers agreed.

“He’s the next one,” Byers said. “New York City adores Isaiah Washington. They love the kid. They support the kid everywhere he goes. Not only has he tore up the AAU circuit, but all the high level tournaments here in New York City. … Right now, New York City belongs to him. They’re going to follow him. Minnesota has basically gained a whole new spectrum of fans with Isaiah going there.”

The Jelly T-shirts being sold in New York might not be popping up all over Dinkytown, however. Pitino checked with the U’s compliance office about NCAA rules regarding a player bringing what amounts to an unofficial brand to the Gophers. According to the U, Washington and his family do not own a Jelly Fam trademark, and they have not profited from the name. The NCAA prohibits student-athletes endorsing commercial items, but an athlete can acquire brand apparel on his or her own. Further, third parties are not allowed to produce apparel using an NCAA athlete’s name or likeness.

After dazzling crowds this spring at all-star games from Long Beach to Brooklyn, Washington brought his mini-brand and ballhandling wizardry to Minnesota in June when he enrolled in summer school. Gophers assistant Kimani Young, a Queens native, was instrumental in landing Washington. Washington’s AAU team was New Heights, which Young once ran.

Young played in high school against the last St. Raymond guard to play for the Gophers, Eric Harris, who went to a Final Four in 1997.

Washington’s not afraid of his own lofty goals, saying he wants “to start my own legacy in Minnesota. I want to be Coach Pitino’s first pro.”

Will he fit in?

As an instant spark off the bench in the DeLaSalle gym, Washington has been giving summer-league fans a glimpse of what his role could be backing up All-Big Ten senior point guard Nate Mason this season. Starters Amir Coffey, Reggie Lynch and Jordan Murphy also return to a squad that improved by 16 victories.

“I think our team is going to be great next year,” Washington said. “I’m going to have a big role. Hopefully, the ball is going to be in my hands. I’m going to be learning from the point guard Nate who is there already. He’s going to be a senior. He’s going to be hungry. He’ll show me a lot. Just learning from him is truly a blessing.”

But Washington seems to relish the spotlight, scoring 1-on-1 or dishing no-look crowd-pleasers. DeLaSalle’s gym turned into Rucker Park Midwest at times last month, with New York-flavored playground ball breaking out in Minneapolis.

A couple of minutes into his first game, the 6-1 Washington flew downcourt, split two defenders and flicked in his finger roll — unafraid of Big Ten defensive player of the year Lynch lurking in the paint. Oohs and aahs filled the gym.

Skeptics are wondering, though, about Washington’s defense, and whether his flamboyant game will work in college.

“You’ll see some of that flash, some of that swag that he always plays with,” St. Raymond coach Jorge Lopez said. “But the difference there is he understands it’s a team concept. And he wants the team to win at any cost. So you’ll see more team play.”

It’s up to Pitino to make sure the attention on Washington and #jellyfam hype doesn’t disrupt chemistry for a team facing lofty expectations.

“I’ve got no problem with that coming to Minnesota,” Pitino said. “I think it’s awesome. It’s brought great awareness to basketball. People love it. … But if he tries to do one of those layups at Michigan State and it gets punched into the student section, we’re going to have to have a conversation with him about it. He knows that. And I told him, ‘Isaiah when you come here, people are going to know who you are. That’s a good a thing. Handle it the right way, and hopefully you play here, have a great career and go on one day to play for money and market yourself even more.’ ”