Ben Shelton was still in diapers, not even a year old, the last time an American man won the U.S. Open, or any major for that matter.

But the hard-serving lefty calls breaking the drought “inevitable.” And he’s leading a charge that could end the drought two weeks from now in Flushing Meadows.

“The gradual improvement of the ranking of American players over the last three, four years, is proof to where we’re going,” said Shelton, 21. “I think it’s inevitable that we’ll have a Grand Slam champion from our country. I don’t know when it’s going to be or who it’s going to be.”

Andy Roddick claimed the U.S. Open back in 2003. No American man has won a Slam since.

Many view Shelton — who rode a 149 mph serve to last year’s U.S. Open semifinal — as the best bet to end that drought this year.

And the experience of that must-see run — and loss to eventual champ Novak Djokovic — has made him even better.

“You learn a lot from these experiences how best to recover from a tough five-set match, how to get yourself to sleep after playing the night session here, how each court plays different, whether you’re playing out on Grandstand or Court 10 or on Arthur Ashe,” Shelton said. “There’s a lot of things to think about.

“So having a little better idea of just how the tournaments work, the possible situations you could be in, rain delays and different things that can happen … and not freaking out when they happen, knowing that some of these things are going to happen and being OK with them, that’s just our sport.”

Shelton, the 2022 NCAA singles champion at Florida, comes into Flushing ranked No. 13.

There are five American men in the ATP Top 20 for the first time since the week of Feb. 24, 1997.

“It’s a testament to the work we’ve put in here in the United States in the last 15 years in tennis,” Shelton said. “You see a lot of guys breaking through around the same age, that at whatever time, they were developing, we were doing something right. That’s a lot of credit to the culture we’ve built here with American tennis and the USTA. … I’m just excited to be a part of it, along for the ride.”

Some think Shelton is driving the bus.

John McEnroe has tabbed him to eventually win a Slam, and Chris Evert picked the world’s hardest server to advance the furthest of the American men in Flushing.

“I’m going to pick Shelton, only because [of] that lefty serve,” Evert said. “I just think he gets so many free points off that serve. I’m just going to pick him to do the best of the American players.”

To do so, he’ll have to get past Monday’s first-round foe Dominic Thiem, the 2020 Open champ.

“It definitely has some hype for a first-round match,” Shelton said. “I love playing in those big type of moment matches. I hate to see it’s Domi’s last Grand Slam, because when I was starting to get into tennis, that was one of the guys who was killing it on TV every single week.”

Shelton is joined by No. 12 Taylor Fritz, No. 14 Tommy Paul, No. 16 Sebastian Korda and No. 20 Frances Tiafoe. Who’ll be the first of that group to win a Slam?

“Well, if you think I’m going to say anybody else but me, you’re crazy,” laughed Tiafoe, who opens Monday vs. fellow American Aleksandar Kovacevic. “It’s hard to say anyone but myself. But ability-wise all those guys have capability of doing it. Let’s go with [Korda] probably. I like his game. He’s super, super complete.”

Shelton beat Tiafoe in last year’s Open quarterfinals before falling to the eventual champion Djokovic in the semis.

If the seeds go to chalk, Shelton and Tiafoe would face off in a third-round rematch, with the winner possibly meeting Djokovic in the fourth round.