WASHINGTON — Juan Soto is one of those rare talents who makes every part of the game interesting and at 20 years old will be key to the Nationals’ success for years to come.

There is the unique way he takes pitches — as he gets himself locked in, he practically moonwalks in the box after he takes a pitch — and, yes, he has been known to grab a certain part of his anatomy.

Cardinals starter Miles Mikolas returned the gesture during Game 1 after he retired Soto with the bases loaded on a ground ball. The pitcher said it was all in good fun and Soto said he had no issues with the gamesmanship.

Soto does all of this to get himself motivated and get the pitcher off his game. Soto is learning at a rapid pace, and no matter how this postseason turns out, the kind of experience he is gaining — a wild-card win, a stunning victory over the Dodgers and now a 2-0 lead in the NLCS over the Cardinals with Game 3 set for Monday night at Nationals Park — will help immensely.

Soto said all his actions in the box make him a better hitter.

“For me, you can’t put pressure on yourself,’’ Soto told The Post. “Because if you put pressure on yourself, it is going to be more difficult to succeed. That is just my mindset. I have to be positive in the box. You never want to pull yourself down.’’

This mindset comes from his family.

“I’ve always been taught you have to stay positive and keep thinking the right way,’’ he said.

For the postseason, Soto has hit two home runs, including that monster blast versus the Dodgers’ Clayton Kershaw in the NLDS. He owns six RBIs. No Nationals player has more, and Soto has one more RBI this October than superstar Anthony Rendon.

Soto will be a thorn in the side of the Mets for years to come. The lefty batted .282 this year with a .949 OPS and 108 walks.

“It’s been amazing,’’ Soto said of the postseason journey. “I never thought it was going to be like this. It’s really fun to play in front of all the crowds and all the good players in the game.’’

Stephen Strasburg will try to pitch the third straight gem by a Nationals starter, but he is running into the Cardinals’ best pitcher, Jack Flaherty.

“Playing behind the pitching staff we have makes you play better,’’ Soto said. “And being at home it’s going to be really loud. I love that. Two more games. Concentrate and win this.’’

Soto made the smart play in the seventh inning of the Nats’ 3-1 Game 2 victory, keeping Paul Goldschmidt’s wicked line drive in front of him with Max Scherzer and the Nationals leading 1-0. That was the first hit Scherzer allowed.

“It’s tough,’’ Soto said. “You don’t want him to get in scoring position. You have to know we are in the playoffs and every error counts. You have to consider the game situation.’’

Scherzer said Soto made the right play.

Nationals manager Dave Martinez is impressed every day by Soto.

“When I first met him, at 19, when I first saw him, how poised he was, how he did everything, almost like very methodical how his thought process is,’’ Martinez said.

“Now we’re in the postseason and nothing seems to bother him, he just wants to go out there and have good at-bats and play good defense and help us win.’’

Soto’s routine in the box is different, but Martinez understands what he is doing.

“It’s a routine that he uses to get to the next pitch,’’ Martinez said. “When you talk to him, he really feels like that’s his batter’s box, he owns that batter’s box. When he does that, it’s basically just saying, ‘Hey, I’m going to get back in here and I’m going to get ready to hit the next pitch.’ If he misses one or whatever or if he takes one, it’s just his way of saying, ‘This is my batter’s box, it’s part of the game, we got a game, it’s me against you, and I’m going to try to beat you.’ ’’

That’s a wonderful winning attitude to have from such a young player.