Christian Pulisic is but 20 years old and the number of effusive words already written about him is staggering.

His classic speed. His majestic acceleration. His touch, which allows him to keep the ball so close to his feet that defenders can only trip or wave at him as he flies past. The near clairvoyance with which he finds space amid a thicket of defenders near the goal. The way he shoots, like an archer. The way he sets his jaw, like a bouncer.

To be clear, the enthusiasm is warranted. Christian Pulisic is the most talented player in American soccer history. And, should he pull it off, what he is about to do -- that is, play for Chelsea in the English Premier League -- will be one of the most impressive feats in American sports history. Yes, Tim Howard played for Manchester United, but he was a goalkeeper; and yes, Clint Dempsey and Landon Donovan made the move to the EPL as well, but they debuted at smaller clubs in Fulham and Everton.

Pulisic is different. By joining Chelsea, he is the first American aiming to star for one of the game's largest clubs. Nearly half the population of the planet watches the Premier League, more than 3 billion people a season. If Pulisic, a young, fresh-faced American, succeeds -- if he scores and dazzles and captivates fans in the U.S. and Europe and China and India and all over Africa -- it changes the calculus on him. His ceiling isn't Landon Donovan anymore. It's Lionel Messi.

The 20-year-old is already the most expensive American player of all time. Will he become the Premier League's next big star? Jasper Bastian for ESPN

On a dank day in Dortmund, Germany, this spring, I meet Pulisic at a restaurant in the city center. He is dressed Euro-casual, in tight jeans and a black hoodie. I notice the sweatshirt right away because it has words written in circles on the sleeves.

"It's from the Uninterrupted guys," he says. "LeBron started this thing with 'More Than an Athlete,' and they sent me one."

Pulisic typically has presented himself as more quiet than brash, but knowing the move he's about to make, the sweatshirt makes me wonder if something has changed. It wouldn't be crazy. Science tells us that if a person picks up two objects at the same time and they have identical weights but different sizes, the larger object is the one that will actually seem lighter. (It's true: Try it with an iPhone and a Kindle.)

This phenomenon has to do with the incredible power of human expectations: We expect the bigger thing to be heavier, so it feels lighter. In sports, the work of becoming a legend is the same either way, but if you make it look bigger, then actually doing the lifting might feel easier. Many superstars have done it this way: Tiger Woods when he said "Hello, world"; LeBron when he welcomed comparisons to Michael Jordan before he was out of high school.

So maybe Pulisic has decided he wants the attention and limelight and microphones that will come at Chelsea. Maybe he is ready to stand up and make a grander statement on, say, pay equity in soccer or the development model in the United States. Maybe he wants to speak.

"You're part of it then?" I ask Pulisic about Uninterrupted. His forehead crinkles. His eyes drop.

"Um, not like part of it," he says. "I support it, I guess you could say." Later, he explains that the fame and the platform might be the bit about his Chelsea move that most challenges him, because he doesn't particularly like being famous.

Fair enough, I tell him, except he just made a career move that guarantees the greatest scrutiny an American soccer player has ever received. He sighs.

"It's definitely one of the hardest parts of my life," he says, stressing that he really does appreciate having fans who support him and really does understand why people stop him for a selfie or an autograph.

"I just hope people realize it's tougher for some of us," he says. His voice lowers. "At times, you just want to be alone."

Pulisic and teammate Felix Passlack, right, were two of Borussia Dortmund's most promising youth players. Alexandre Simoes/Borussia Dortmund/Getty Images

I have schnitzel, Pulisic has a salad, and then he leads me through the Borussia Dortmund locker room at the team's stadium. He stops in front of his locker and explains, with a touch of wistfulness, that when he saw his jersey hanging there for the first time in 2016, it was the "coolest thing in the world."

Outside on the field, standing in front of the towering south stand where 25,000 fans crowd together to form the so-called Yellow Wall during games, he almost giggles as he reminisces about the noise in the stadium after a goal.

"You hear the stadium announcer yell 'Christian!' and then everyone yells your last name back," he says, cocking his head as though it is echoing right now. "I mean, scoring a last-minute goal in front of this wall, and you see the beer flying everywhere and ..."

His voice trails off. Leaving for Chelsea might have been a fairly straightforward business decision for Pulisic, but the departure from Dortmund is difficult. Dortmund was a haven for Pulisic, a place to develop his game and discover how he wanted to present himself as an athlete. In soccer terms, Dortmund was Pulisic's boyhood home.

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Club scouts found him when he was 15, smitten after watching Pulisic play at a U.S. youth national team tournament in Turkey. They saw then what Chelsea officials see now: a soft, silken touch more European than American. For Dortmund, which has a renowned youth development academy, he seemed a perfect fit.

"We only sign players from foreign countries if we're extremely confident that he's becoming a player for the professional team," Lars Ricken, Dortmund's youth coordinator, tells me at the team's training facility, adding that he sees Pulisic as one of the club's biggest success stories.

Pulisic arrived in Germany from Hershey, Pennsylvania, when he was 16. He initially struggled with school -- to this day, he says, he's still not sure what classes he attended at first since he didn't understand a word of German at the time -- but blossomed quickly on the field.

Many soccer analysts say success at the highest levels of the sport comes down to millimeters. If the space between the ball and a player's foot is much wider than that, he isn't truly in control of it. Pulisic's gap, even as a teenager and even when he was sprinting, was minuscule. He was called up to Dortmund's first team in less than a year. "We don't buy stars," Ricken says now, with obvious pride. "We build them."

Pulisic became the youngest non-German to ever score in the Bundesliga (he celebrated by dabbing). Then he became the youngest Dortmund player to ever play in the Champions League. He appeared in 127 games over four seasons for Dortmund and helped the team win the German Cup in 2017.

Along the way, he hung on to plenty of his American tendencies -- "I remember him driving like two hours to Frankfurt to get burritos sometimes," says Dortmund winger Jacob Bruun Larsen, his former roommate -- but he also worked to connect with the city and the fans. Instead of sloughing off the language barrier, he embraced it, practicing his German to the point where he was able to do interviews on television. His grammar wasn't perfect, but the effort endeared him to the team's supporters.

Pulisic arrived in the German industrial town of Dortmund when he was just 16. It became his first home away from home. Jasper Bastian for ESPN

They loved that he tried, loved that he put his head down and grinded in the blue-collar image of Dortmund players who came before him. He trained rigorously and diligently. He battled against juggernaut Bayern Munich. He scored important goals, like the gorgeous lob over Benfica's goalkeeper in the Champions League. He also suffered through one of the worst weeks in the club's history. In 2017, as the team traveled from its hotel to the stadium, its bus was struck by explosives planted by a deranged fan.

Pulisic has rarely spoken about that episode, and his eyes soften as he recounts the fear he felt when the windows of the bus exploded and rockets of glass flew everywhere. "We were just going to a normal game, like always, and there was just a really loud bang," he says. "It was so loud, I couldn't hear anything. I was confused."

He pauses. "I just remember [Dortmund goalkeeper] Roman Burki next to me grabbed me and pulled me under the table because he probably recognized what was going on before I did. We were just so scared."

Pulisic looks away, his voice slowing down. "And then I hear Marc screaming. ... He was right across from me. ... And I see blood. ... And he's yelling for the doctor. And everyone's screaming at the bus driver, 'Driver, keep going!'"

Marc Bartra, a defender, was struck by the glass and had shards embedded in his arm. He underwent emergency surgery that night. There were no other serious physical injuries among the players, but the emotional fallout from the episode was significant. Pulisic was 18, living on his own in Germany.

He had to deal with knowing someone had tried to kill him and his friends. He had to deal with staying at the same hotel before another game. He had to deal with getting back on the team bus without feeling his skin crawl. He had to figure out how to process it.

It was a hyperintense event within a hyperspeed maturation. Pulisic learned how to shop for groceries in Dortmund, how to cook for himself in Dortmund, how to get ready for work each day in Dortmund. After the bus attack, he learned how to confront his own demons and move on from a nightmare in Dortmund.

"I've changed a lot," he says at one point, "a lot on the soccer field but maybe even more off the field."

As we walk back up from the locker room, he looks around and says, "In a lot of ways, I grew up here."

The young American is off to a flying start with the Blues, scoring two goals and winning a penalty in an eight-minute span in a preseason friendly against RB Salzburg. KRUGFOTO/APA/AFP/Getty Images

Pulisic decided to leave Dortmund on Jan. 2. Chelsea shipped $73 million to the German club, making Pulisic the most expensive American player sold in soccer history. (It's not close either: Defender John Brooks is second after his $22.5 million jump from Hertha Berlin to Wolfsburg in 2017; Dempsey's shift from Fulham to Tottenham in 2012 cost Spurs only $9.6 million.)

To Pulisic, the move is part of a progression, the obvious next step on his path. It is natural to him, expected even. In fact, the most animated I see him get over the course of our conversations is when I mention how he has often been called a "wonderboy" by broadcasters and fans and analysts, a term that was originally flattering but now seems to strike him as borderline demeaning.

"The reason I just don't like to hear it anymore is because I feel like now I've been a part of this enough," he says. "And I think I've earned my spots in teams and shouldn't just be looked at as just a prodigy."

He takes a breath. "I don't see myself as that label anymore. It's just not how I feel."

Pulisic is 20. Kylian Mbappe, star of France's 2018 World Cup win, is also 20 and isn't called a wonderboy or a prodigy -- he's just a superstar. At this stage of his career, Pulisic says, he doesn't want to be compared to other players his age; he just wants to be compared to other players.

That, I assure him, will happen quickly and often in the Premier League. But Pulisic will always reckon with a different contextual comparison because of his nationality. It doesn't especially matter that Mbappe is French when considering his value as a player; France has produced plenty of international stars and will produce more. Pulisic, though, is playing as the face (and legs and feet) of American soccer. If he fails, it isn't clear when another American will have a chance like this.

That reality is no doubt part of why the initial reaction to Pulisic's Chelsea move, at least from outsiders, has been tempered with a fair bit of caution. While Chelsea is a club teeming with stature and success, it is nonetheless known as one of Europe's great powder kegs. Its owner, Roman Abramovich, is a notoriously erratic Russian oligarch who has made 14 managerial changes in 16 years and has cultivated a culture of turnover at Chelsea that a former team employee once described to me as a "combustible nightmare."

What that means for Pulisic is that he will be playing under (no surprise) another new Chelsea manager, Frank Lampard, who was a longtime star player for the club but has only one season of coaching experience. Pulisic also will be charged, at least in part, with replacing Eden Hazard, a Belgian wizard who is generally considered one of the 10 best players in the game. (Hazard left Chelsea for Real Madrid after seven seasons.)

Add in a transfer ban that means Chelsea isn't allowed to sign more players for a year -- ratcheting up the heat on the current crop even more -- and it creates a set of circumstances that are, as Donovan says when we meet up this spring to talk about Pulisic, "concerning to me."

Donovan had a solid spell playing abroad himself, but he really built his legacy on his work with the U.S. national team and in Major League Soccer. Pulisic's task, he says, is something far greater. "I can see it being a massive home run for him," Donovan says. "[But] Chelsea spends a lot of money on a lot of players. They have money forever. They can spend $70 million to bring in Pulisic, and if it doesn't work right away, it's no problem. They can move on to the next player."

He shrugs. "He's not going to be afforded as much leeway if things don't go well as he would at a different club."

Stu Holden, a former national team forward who played with Bolton Wanderers for four years, says the same, calling Chelsea a club with "rich history and tradition" that is also "unstable" and "a bit of a mess."

Even Jurgen Klinsmann, the German legend and former U.S. national team head coach who gave Pulisic his first international call-up, isn't totally sold. He praises Pulisic for "jumping into the colder water" but then adds, "I thought maybe another one or two years in Dortmund wouldn't have been wrong."

What they are all expressing, in one way or another, is the uncomfortable certainty that it will not be enough for Pulisic just to shine with Chelsea; he will have to shine quickly. As Donovan says, there is little doubt about Pulisic's place when it comes to the U.S. national team -- "For the next decade, he's going to be the most important player" -- but it is not so easy to say the same for Chelsea.

Could Pulisic step right in and thrive? Absolutely. Lampard says Pulisic is the kind of player "who wants to take people on, the sort of player the fans are going to like," while longtime defender David Luiz says he believes Pulisic "is going to have a great future with us." And maybe it really will be that easy. But could Pulisic struggle or get injured or find himself on the bench or out on loan to some smaller club? Could we look up next spring and wonder where he went? The list of talented young players who went to England and had that result isn't exactly short.

Nevertheless, Pulisic seems undaunted. He talks about normal nerves and overwhelming excitement and confidence and verve, delivering the sort of steely assurance that is both accepting and dismissive at the same time. Even when I mention the notoriously harsh British news media, he barely wavers.

Pulisic sees this move in soccer terms and little else, and that perspective is probably both healthy and correct. Even the notion that his nationality matters, that being American might help Chelsea sell a few (thousand) more jerseys in the U.S., might be overblown. Chelsea signed Pulisic for the same reason any club signs any player: They think he can help them win. They see his creativity and his ability to play far up the field in Lampard's expected formation. They see the way he chases in the attacking third and the way he pings passes from sideline to sideline.

"I know what kind of player I am," Pulisic says. "And they know exactly the same."

Could he have waited? Could he have stayed in Dortmund? Could he have held out for a situation that didn't involve an unpredictable Russian owner and a superstar whose departure dials up the pressure? Maybe. But it's also hard to say that with a straight face.

"Nobody would turn down that offer, right?" Donovan says.

Done with being compared to his own potential, Pulisic is going to Chelsea to stand on his own. "I know I'm ready for this," he says.

Despite Pulisic's efforts, the USMNT failed to qualify for the 2018 World Cup for the first time in 32 years. Ashley Allen/Getty Images

The game ended on an October night in 2017, and Christian Pulisic saw an assistant coach walking toward him. His throat was sore from shouting. It was steamy at the stadium in Couva, Trinidad, the air hanging heavy. The rain-soaked field was so waterlogged, he heard the squish of the coach's shoes.

The United States had just lost a game it should have won, a game in which it needed only a tie to qualify for the World Cup. Pulisic didn't know whether other teams might have bailed out the Americans by losing too. He looked at the approaching assistant hopefully.

"We're not going," the coach said. Fast. Blunt. Brutal. Pulisic rocked back. In the locker room, team staffers rushed to move out the champagne and beer that were supposed to be part of the celebration. On the field, Pulisic crouched down and cried.

He had scored. He had pushed. He had run. He had never considered, not for a second, that it wouldn't be enough. He had never considered, not for a second, that he wouldn't be playing for his country in the biggest tournament in sports.

As he changed out of his uniform, teammates cried around him. On the flight the next morning, there were wet eyes again. The wound from that evening blistered over and lingered, jabbing at Pulisic for weeks.

"It was," he says now, "the worst night of my pro career, by far."

Nearly two years later, though, the images from that night's failure -- Pulisic burying his head in his hands, pulling his jersey over his eyes, tears streaming down his face -- seem blurred by time and circumstance.

In July, instead of going on the post-Gold Cup vacation that many other top players take, Pulisic joins his Chelsea teammates in Japan on a preseason tour. He signs autographs and takes selfies with fans outside the team hotel. He makes an appearance at a local store with Lampard. He laughs during pre-practice stretching with Luiz. He juggles a ball while wearing a new style of studs that have his name splashed across the heel. The coverage, not surprisingly, is breathless: There are articles about his jersey number (he picks 24) and even a full recap, with video, of a thundering goal he scores during a practice drill.

On the field, Lampard eases Pulisic into the group. He comes on as a substitute and plays a half-hour against a Japanese team, making a few good runs without real result. A few days later, against Barcelona, he is a dervish, whipping runs from both sides and showing no fear as he goes up against the world's most celebrated side. In Austria a week later, he gives Chelsea fans an early glimpse of what's to come: He wins a penalty, pulls off a glorious nutmeg and scores two goals, showing off his superior touch as Chelsea goes up 3-0 inside 28 minutes.

These are only friendlies. The real run of show begins next week, when Pulisic officially enters the most watched soap opera in the world. The fans will be thrumming, Lampard will be stalking the touchline and supernovas like Paul Pogba will be on the opposite side, whizzing along at breakneck pace and demanding a level of excellence from Pulisic that he has never needed to reach so often. It will be fierce. It will be ambitious. It will be daring. "I'm going to go in there," he says, "and play with my same attacking style. I think I'm going to fit in really well."

Two years ago, after that awful Trinidad game, a belief like that felt so far away. At 19, it was hard to be patient, and Pulisic left that night frustrated and antsy, wanting to know how the loss would affect the U.S. team, wanting to know what all of it meant for his chances to move to a bigger club. Two years ago, he wanted to know if his moment would ever come.