WASHINGTON -- As he sat at his locker, taking it all in with a big smile on his face, the Nationals' 19-year old phenom Juan Soto was greeted by various teammates on his first day in the Majors. Bryce Harper, the last Nats teenage phenom, came over to give him a hug. General manager Mike Rizzo and members of the coaching staff came over to offer him congrats for a moment that arrived much sooner than anyone could have expected -- even Soto himself.
The Nationals promoted Soto, the club's No. 2 prospect and the No. 15 overall prospect as rated by MLB Pipeline, to the Majors on Sunday, making him the youngest active player in MLB. He debuted in the eighth inning of the Nationals' 7-2 loss to the Dodgers and struck out after pinch-hitting for Adrian Sanchez.
Soto skyrocket through the club's system, beginning the season at Class A and mashing his way to three promotions in a month, culminating with his arrival in Washington for this series finale against the Dodgers.

"I was in shock," Soto said, motioning to the goosebumps on his arm. "I was so excited, I didn't think that would happen."
Soto has been considered a piece of the Nationals' outfield of the future, but no one could have predicted the future would arrive this quickly. Even though he is not in the starting lineup on Sunday, Soto was promoted to be the team's everyday left fielder. The Nationals will likely limit his at-bats against tough left-handers -- such as the Dodgers' Alex Wood -- and try to make sure they ease him into Major League life as much as possible. But Soto is here to play -- and play everyday.
The team optioned right-hander Jefry Rodriguez to Double-A Harrisburg, and it designated Moises Sierra for assignment to make room for Soto on the roster.

"I didn't think that was going to happen that quick," Soto said. "But I feel very good."
Soto's promotion comes as a culmination of a few events.
For one, Soto has dominated at every level at the plate. He ripped through Class A Hagerstown with five home runs and a 1.300 OPS in 16 games. He mastered Class A Advanced Potomac, as he posted a 1.256 OPS and homered seven times in 15 games. And he had been doing more of the same at Double-A, with a .981 OPS in eight games.
Soto would have likely stayed there to continue his development had the Nationals not been pelted by injuries in the outfield. Adam Eaton is still recovering from left ankle surgery, Brian Goodwin is still a ways off from returning with a wrist injury, top prospect Victor Robles is still recovering from an elbow injury, Rafael Bautista required season-ending knee surgery this week and Howie Kendrick ruptured his Achilles tendon on Saturday, ending his season.

Rizzo has shown that he will not hesitate to promote a player because of age. There have been eight 19-year-old position players promoted to the Majors since 2001, and Rizzo has had a hand in three of their callups: Justin Upton ('07), Harper ('12) and now Soto. Although Rizzo believes players can be rushed to the Majors and their progress can suffer a setback, good players cannot be ruined.
"If you can play, you can play," Rizzo said. "That was the thought process that went in with this player. He's passed every test that we've thrown at him. And we feel that, because of the circumstances, he's our best option to help us win baseball games in the big leagues and to forward his developmental process."
Soto said the biggest difference between each level of the Minors was the number of offspeed pitches he saw, with pitchers increasingly trying to tempt him to chase pitches out of the zone. That is the one area the Nationals want him to be aware of, trying only to swing at pitches in his strike zone as much as possible.
But, the Nationals believe Soto will pass that test as well. Scouts rave about his plate discipline and mastery of the strike zone. The Nats rave about his makeup, preparation and maturity level. And Rizzo said there was no pause to promote Soto because he believes he is mature beyond his years.
"If a guy's ready, he's ready," manager Dave Martinez said. "Doesn't matter his age. I've watched this guy, his ability to hit the ball all over the field is impressive. I've seen him hit balls to left-center field like right-handed hitters. I was just amazed at how mature he was in the batter's box."