(CNN) The youngest foreign player to score in the German Bundesliga; the youngest player to score two Bundesliga goals in a single game; the youngest player to score for the US men's national team; the youngest player to captain the USMNT and the most expensive American player (transfer fee-wise) of all time.

These are just a handful of the records that Christian Pulisic has broken during his career -- and he's just 20-years-old.

The American is playing in the English Premier League this season, after moving from Borussia Dortmund to Chelsea in January for $73 million (£58 million).

Pulisic battles for the ball with Liverpool's Mohamed Salah during the UEFA Super Cup.

He made his debut for the Blues against Manchester United as a substitute but made his first start in the European Super Cup loss to Liverpool , giving the Chelsea fans a glimpse of his talents with an impressive performance.

But his footballing journey from Hershey, Pennslyvannia -- known as "The Sweetest Place on Earth" due to Hershey's chocolates being manufactured there -- to London has been quite something.

An English taster

Born in Pennsylvania to Kelley and Mark Pulisic in 1998, Pulisic was exposed to football from an early age.

Both his parents played collegiate soccer at George Mason University, with Mark also playing professional indoor football in the 1990s and latterly becoming a coach.

But Pulisic's passion for the sport really blossomed thanks to the year his family spent abroad in the small English village of Tackle -- near Oxford -- after mum Kelley did a teaching exchange which saw the family relocate to the UK in 2005.

Christian Pulisic (bottom row, second from left) with his Brackley Town team and coach Robin Walker.

Keen to foster the interest in the sport that his son had already shown, Mark contacted local clubs to see if there was an opening for the seven-year-old, eventually plumping for the Northamptonshire club Brackley Town.

It was a 30-minute drive from their home in Oxfordshire to the club but for Mark, the prospect of his son playing more competitive football was vital to continue Christian's development.

And after his first trial at the club, the coach of Brackley Town's Juniors Under-8 team Robin Walker could already tell that the young Pulisic might become a special player.

"You could see straight away ... his touch, his movement, his passion, he had something about him. I said, 'we'll sign him up,'" Walker told CNN Sport.

As a seven-year-old, Pulisic was a year younger than the rest of the team and physically smaller than his teammates, but his "never say die attitude," according to Walker, stood him in good stead.

"He got fouled, he got straight back up again," said Walker. "And that tenacity really took me by surprise. He was better than all the players that we had."

Christian Pulisic (bottom row, third from left) with his Brackley Town teammates, coach Robin Walker and ex-Chelsea player Gavin Peakcock.

Having level-headed parents also played a key role in keeping Pulisic on the right track.

"They're not the sort of the head in the sky sort of parents," Walker said. "His dad was quite firm but in a sort of relaxed manner.

"You get some dads shouting on the touchline and yelling their head off. That wasn't Christian's dad. He was quite firm. He pushed Christian."

Mark made the most of the family's time in England, taking Christian to professional games to see the likes of Manchester United and Tottenham Hotspur.

"He really fell in love, became obsessed with the sport," Mark told the Guardian in 2016 about their time in the UK.

Returning home

If his passion for football was fostered in England, Pulisic's footballing roots are in Pennsylvania.

Before leaving for their year abroad at Oxfordshire, Pulisic had been part of his local U.S. Soccer Development Academy club, Pennsylvania (PA) Classics, and upon the family returning in Hershey, he re-joined the club.

Steve Klein -- academy director at PA Classics and Pulisic's former coach -- has known the Chelsea player since he was a young kid, but only really saw his true potential when he reached his teenage years.

Pulisic faces England for the USA Under-17 team.

"Once he was 13 or 14 then you could start seeing that this kid's pretty special," Klein remembers.

"He might be someone that could be in a national team. He was just very technical with both feet. He was always very quick. You could see that from an early age, his reading of the game was just better."

Pulisic had training sessions with Barcelona, Chelsea, Porto, PSV Eindhoven and Villarreal and was also on the USA national team's radar -- he began playing for the Under-15 team in 2012, aged just 13, and went on to score 21 goals in 28 international appearances over the next two years.

Once more though, Mark was keen to temper expectations about his son, according to Klein.

European adventures

With the world seemingly at his feet as a 16-year-old, Pulisic had offers from all across Europe to further develop his game.

With an offer from Spanish giants Barcelona on the table, Mark made the decision for his son to join German side Borussia Dortmund, a club renowned for being able to transform rough diamonds into highly valued players.

So, in February 2015, 16-year-old Pulisic joined the eight-time German champions and was immediately moved to their Under-17 side.

Pulisic of Dortmund celebrates after scoring for the Borussia Dortmund Under-17 team.

In the Dortmund academy set-up, the youth teams are well integrated with each other, with players regularly interchanging between the age groups and the senior side.

As a result, Marc-Patrick Meister -- head coach of the Under-19 team when Pulisic joined -- saw a lot of the American and was immediately impressed.

"A lot of times he was part of our (the Under-19's) training session," says Meister.

"He had an outstanding level from the first day he became a member of Borussia. Later on, even the professional coaches David Wagner, Jurgen (Klopp) and Thomas (Tuchel) recognized very fast that this is an outstanding boy and with an outstanding mentality to work hard even against forces which are against him on the pitch and outside the pitch."

To help Pulisic acclimatize to the move to a foreign country, with an entirely new language, father Mark also came over to Dortmund and joined the club as a coach.

Meanwhile Pulisic's dedication to adjusting to life in Dortmund by learning the German language was key to his integration

Pulisic with the DFB Cup after Dortmund beat Eintracht Frankfurt in 2017.

"When people ask me about Christian, I compared him with Son Heung-Min ," Meister said. "In 2009, I worked with Hamburg SV.

"We had a cooperation with the Korean Football Association who traveled over for 10 days, stayed there and we choose three boys for a one year trial period from the KFA to Hamburg.

"At the same age, 16 years old, Son became part of my team in Hamburg and he was the one out of the three who was so keen, and he worked a lot to be able to understand first and then even to speak the German language which is very hard."

Back to where it all began

In November 2018 -- two months before his big-money move to Chelsea was confirmed -- Pulisic said he would be "open" to a move to the Premier League.

But after suffering injuries and losing his place to another upcoming young star -- Jadon Sancho -- a move away from the German side looked less likely.

Then after signing for Chelsea in January, having spent the second half of the 2018/19 season on loan back at Dortmund and managing to rekindle some good form, the excitement has picked up for Chelsea fans.

Pulisic is joining a team that has lost the talismanic Eden Hazard to Real Madrid, though club legend Frank Lampard has replaced Maurizio Sarri as manager.

Pulisic runs past Oriol Busquets of Barcelona during their preseason friendly match.

But despite all those obstacles, Alex Goldberg -- Chelsea fan and host of 'The Byline' podcast -- believes Pulisic is perfectly poised to be a success.

"Obviously, Chelsea are not in the greatest position right now, losing Eden Hazard and having a transfer ban," said Chelsea fan and host of "The Byline" podcast Alex Goldberg.

"It looks like he's playing some really confident football and I think the big thing is that he is 20 years old and has top-level experience.

"A lot of the youth players that Chelsea fans want to play, including myself, are 20 years old and are coming from the Championship in England but Pulisic has years and years of Bundesliga league experience."

An American Chelsea superfan, Goldberg has amassed a large following with his hot takes and passionate support for the Blues resulting in videos from Chelsea players including Callum Hudson-Odoi and Mason Mount, thanking him for his support.

Goldberg believes having an American playing for one of the biggest clubs in the Premier League will do wonders back home.

Pulisic captains the United States against Curacao in the CONCACAF Gold Cup.

"I definitely do think that Pulisic is going to improve as a player being at Chelsea which then indirectly improves the United States men's national team," Goldberg said.

"Also, just what Pulisic has done for young American players has been great. Showing them that there is a path.

"We're starting to see a couple more legitimate players -- like Weston McKinney and Timothy Weah -- really make names for themselves.

"Especially if he succeeds at Chelsea, what he will do for the sport of football in the US is probably incalculable."