Juan Soto struck out on four pitches in his major league debut with the Nationals on Sunday. (Geoff Burke/USA Today Sports)
Columnist

When Juan Soto, 19, heard Saturday that he had been called up to the majors by the Washington Nationals, he instantly got goose bumps.

“I was in shock. All my [hairs] went up,” Soto said Sunday, running his hand up his forearm. “I was so excited. I didn’t think that was going to happen.”

Funny, I had the same reaction.

Few events give fans goose bumps like the arrival of a teenager in the majors. With its vast anecdotal history, enormous stat base and a long, tough learning curve even for great athletes, baseball has an invisible wall against teens. When one appears, he must leap over decades of rush-’em-and-ruin-’em warnings and analytics-based projections about how each level of the game must be mastered or it may never be totally internalized.

At 23, if you’re a real prospect, you’re probably in the majors. At 22, maybe. At 21, that’s still hot stuff. At 20, pay big attention, such as Braves outfielder Ronald Acuna Jr., who is now the second-youngest player in the majors — after Soto.

But 19? Come on, even if injuries have sped a player’s rise, as with Soto amid the Nats’ injury tsunami, how good do you think this kid is?

In the past 16 years, Soto is only the ninth teenager to be brought up to the big leagues. The others include the best player in the league, Mike Trout; Bryce Harper, who will probably sign a $300 million-plus contract after this season; Cy Young Award winner Felix Hernandez, who had 143 victories before he was 30; Justin Upton, a four-time all-star; and Jose Reyes, a batting and stolen base champion. The other three weren’t so hot. But you get a sense of the possibilities and odds.

Ty Cobb, Mickey Mantle, Ken Griffey Jr. — stop me if you have heard of any of these guys — Al Kaline and Mel Ott also emerged as teens. Such players seldom arrive full-blown. But stardom comes in a year or two.

Other than that, there’s no reason to be excited about Soto.

Except that his batting average in three years rocketing through the minors was .362 at all stops. This year, in three leagues and 39 games, he hit .362 with 14 homers — one of them 460 feet long — and 52 RBI. For a full year, that would equal more than 50 homers and more than 200 RBI.

He’s not that good. And his entire pro experience is still only 454 at-bats because he was hurt much of last year. But his stats are scary. And in baseball, numbers, even minor league numbers if they are astronomical, usually matter.

Soto’s minor league slash line (.362 batting average/.434 on-base percentage/.609 slugging percentage), plus 22 homers and 102 RBI, is not that different from Ted Williams’s and Willie Mays’s. They erupted in the majors at 20. “If you can play, you can play,” Nats General Manager Mike Rizzo said.

Good-to-very good minor league hitting numbers may mean something or nothing. But almost-unbelievable stats, such as Soto’s .757 slugging percentage in the minors this spring, usually predict a good-to-great big league career. I searched for current players who had hit over .350 in their bush league years, no matter where or how long, to find out what a “low expectation” might be. The best comparison I found was, ironically, Howie Kendrick, whom Soto essentially replaced after the veteran tore his Achilles’ tendon Saturday. But even Kendrick, who has been an all-star, has 1,607 hits.

Luckily for the rule of reason in D.C. baseball, Soto struck out on four pitches as a pinch hitter in his major league debut in a 7-2 loss to the Dodgers. He received an ovation coming to the plate and cheers when he walked away unrequited. It is not his first at-bat but his next hundred or more before Adam Eaton returns, perhaps in late June, that may give a sense of what Soto offers now and for 2018.

The implications are large. The answer to “How much would the loss of Bryce Harper hurt the Nats” is probably, “That depends a lot on Soto.”

Everyone knows the five-tool talent of speedster Victor Robles, the Nats’ top-rated prospect. But the Nats must possess an elite, left-handed, middle-of-the-order bat such as Soto, not another righty, to field a fine total lineup, assuming Harper leaves in free agency. The combo of Robles, ranked as high as the fifth-best prospect in baseball, and Soto, who has shot up from 58th to 15th, lets the Nats sleep well and smirk a bit at those who say their window is closing.

Few in major league baseball would offer Harper the biggest contract in history if the Nats realistically see Soto and Robles as future stars who will join Eaton, signed through 2021, in their outfield. If Harper left, they would get a compensation pick, which Rizzo probably would turn into a starting player, as well as the flexibility to spend all that money on other players, including Anthony Rendon.

But Soto’s ability to become a standout is a monumental “if.” He wasn’t even expected to be called up until, perhaps, September. Now, injuries have sidelined five outfielders: Eaton, Kendrick, Brian Goodwin, Robles and Rafael Bautista. Injury, or baseball fate, now gives the Nats their first big look at Soto.

“When a player’s up at 19, you know how much the team believes in him,” Dodgers President Stan Kasten said, “though in Atlanta we had to bring up Andruw Jones at 19 because he wouldn’t give us a choice: minor league player of the year back-to-back.”

Last year, Soto, who is from the Dominican Republic, conducted his few interviews in Spanish. On Sunday, he answered questions in the Nats’ clubhouse in fluent English. That fast “learning curve” thing again?

Was his jump to Class AA Harrisburg, where he hit .323, difficult for him? “A little bit, yeah. They throw more off-speed for me — for everybody. That was the big change,” said Soto, who doesn’t seem worried by breaking balls yet.

“I’m aggressive every time. And I look for a good pitch. Hunt the fastball. . . . If I look for the fastball, the breaking ball is going to be easy,” said Soto, whose greatest strength, according to scouts, is his eye for the strike zone, seldom chasing bad pitches and walking about as much as he fans.

Soto’s early arrival gives the Nats a relaxed look at a key player whom they wouldn’t have been able to analyze so thoroughly otherwise. Every aspect of his learning curve stuns and pleases them, even his grasp of questions from his teammates and his fluid answers that allow him to soak up big league info at the fastest possible pace.

“I just was in the clubhouse [Saturday], and the manager came and said, ‘Hey, you’re going to the big leagues,’ ” said Soto, composed but smiling. “I text all my family. They were happy. . . . Now I’m strong and ready to go.”

Just a year ago, Soto seemed a poorly defined figure in the distance — injured, still learning a language and impossible to classify as a talent.

Now he has ripped through five leagues, hitting .356, .429, .366, .371 and .323. The Nats just hope Soto’s numbers translate. Maybe it’s a clue: His English already has.

For more by Thomas Boswell, visit washingtonpost.com/boswell.