Francis Tiafoe, the son of West African immigrants, has become one of the most prominent rising tennis players. In December, at 15, Tiafoe, of Prince George's County, became the youngest player ever to win the Orange Bowl, the most prestigious international title for boys under 18.

He makes an exception for Tiafoe.

“He is definitely the real deal,” McEnroe says. “He has got all the tools. And he has a real good sense of how to play — what shot to hit at the right time, when to sense his opponent is feeling the pressure so he doesn’t have to do too much, or when he has to do a little more. I often see kids who may hit the ball really well but don’t know how to play the game. Francis does. And he has a tremendous amount of joy and passion when he plays.”

More than a decade has passed since an American man won one of the sport’s four major titles or reached No. 1 in the world. Andy Roddick, who retired in 2012, was hailed as the savior of American men’s tennis upon winning the Orange Bowl in 1999, the year after Federer. And he went on to win the U.S. Open and reach No. 1 in 2003, shortly after turning 21.

But two other American boys who won Orange Bowls have been relegated to sporting obscurity: Brian Baker, who compiled an 18-30 record in the pro ranks, and Timothy Neilly, who peaked at No. 852.

McEnroe worries about the burden that comes with Tiafoe’s world-caliber junior results. “Let’s be honest: We’re at a pretty big low in men’s tennis at the top right now. Obviously part of the reason Francis is getting so much attention is tied into that. He’s our next great hope. That’s a lot for anybody to deal with.”

This summer represents a major test. He’ll face the world’s best 18-and-under players in the three remaining junior Grand Slam events: the French Open, Wimbledon and the U.S. Open. But he’s also entering a handful of pro events to test himself against grown men, as he did in Vero Beach, where he lost in the second round to 27-year-old Gregory Ouellette, a former all-American at Florida who’s now ranked 550th in the world.

Humility is an effective teacher, Kouznetsov says, and Tiafoe will face even stiffer competition in the top-flight pro events he is eyeing later in the summer.

Because he is an amateur, Tiafoe can accept only nominal prize money to cover his travel expenses. But his parents are in no rush for their son to turn pro, despite the huge financial windfall it might represent. In fact, they would like to see him attend college first.

Tennis may indeed translate to a lucrative career, his father acknowledges. But how long will that career last, he asks: A decade? Fifteen years? What next, without a college education?

“When you’re good in sports in this country, the money comes so fast you don’t even know what to do,” Tiafoe Sr. says. “But the education has got to be there. When money comes, that’s when people come, too. Managers, advisers. So you should be able to tell them what to do. You should be smarter than them; not them smarter than you.”