Little over a year after making his professional debut, USA international Weston McKennie became the seventh Bundesliga-based American to play in the UEFA Champions League when Schalke welcomed Porto to the Veltins-Arena on Tuesday.

bundesliga.com takes a look at the star-spangled sextet the 20-year-old will be joining in the history books...

Christian Pulisic

Age: 20
Club: Borussia Dortmund
UEFA Champions League appearances: 15

Christian Pulisic had already become the second youngest non-German to score in the Bundesliga, and the youngest ever player to register two goals in one Bundesliga game, when the Borussia Dortmund megastar masterminded Benfica's downfall in a Champions League round of 16 meeting on 8 March 2017.

The Hershey sensation scored one and laid on another against the Portuguese powerhouse, a feat that took him into the annals as the youngest American to register a goal and assist in a single Champions League match and propelled BVB into the quarter-finals. Clocking in at 18 years, five months and 18 days, it was his eighth of 15 Champions League outings before the age of 20.

Christian Pulisic has taken on some of Europe's biggest clubs, including Real Madrid. © gettyimages / Baron / Bongarts

Fabian Johnson

Age: 30
Club: Borussia Mönchengladbach
Previous clubs: 1860 Munich, Wolfsburg
UCL apps: 10

Fabian Johnson was only a spectator for Wolfsburg's debut plunge into the Champions League in 2009/10, Felix Magath's side - swashbuckling Bundesliga winners the previous season - bowing out at the group stage. The former 1860 Munich youth player's time would eventually come in the colours of current employers Borussia Mönchengladbach, however, in the lion's den that was 2015/16 Group D.

It was a chastening experience for the tournament debutants, who brought up the rear behind Manchester City, Juventus and Sevilla, but Johnson made the most of the opportunity, registering two goals and as many assists in five appearances. He added another five European outings to his CV the following campaign, as Gladbach finished third in a group containing Barcelona, Man City and Celtic.

Fabian Johnson (r.) played some of his best football during Gladbach's debut Champions League adventure. © gettyimages / Bryn Lennon

Julian Green

Age: 23
Club: Greuther Fürth
Previous clubs: Bayern Munich, Hamburg, VfB Stuttgart
UCL apps: 2

Julian Green had the world at his feet after being snapped up by Bayern Munich's U17 team as a 14-year-old. He signed his first pro deal with Germany's most successful club in January 2014, but things didn't quite work out as hoped for the Floridian forward, who managed just four competitive appearances either side of a loan stint with Hamburg before leaving for VfB Stuttgart in January 2017.

Two of those outings came in the Champions League, with Pep Guardiola handing Green his European debut as an 88th-minute substitute for Mario Götze in a group-stage victory over CSKA Moscow in November 2013. Green enjoyed a longer run-out under Guardiola two years later, completing 68 minutes of a 2-0 win at Dinamo Zagreb before being replaced by Arturo Vidal. Nowadays, the USA international plies his trade in Germany's second tier with Greuther Fürth.

Julian Green's (r.) two Champions League appearances to date came under Pep Guardiola (l.) at Bayern Munich. © gettyimages / Alexander Hassenstein/Bongarts/Getty Images

Jermaine Jones

Age: 36 (retired)
Previous clubs: Eintracht Frankfurt, Bayer Leverkusen, Schalke, Blackburn Rovers, Besiktas, New England Revolution, Colorado Rapids, LA Galaxy, Ventura County
UCL apps: 27

The son of an American serviceman, Jermaine Jones was born and raised in Germany. After graduating from Eintracht Frankfurt's youth academy, he joined Bayer Leverkusen and later moved to Schalke, where he took his number of Champions League appearances to 27, a competition record for an American, shared with DaMarcus Beasley.

Jones helped himself to a couple of goals along the way in games against Galatasary and Rosenborg - not as many as U.S counterparts Sacha Kljestan (three) or Beasley (six) - but a decent return for a holding midfielder all the same. He also turned out a further 11 times in the UEFA Europa League, with Tim Howard and Brad Friedel the only Americans to have racked up more matches in UEFA competition.

Jermaine Jones enjoyed five seasons of Champions League football, including four with Schalke. © gettyimages / DIMITAR DILKOFF/AFP/Getty Images

Landon Donovan

Age: 36 (currently without a club)
Previous clubs: Bayer Leverkusen, San Jose Earthquakes, Bayern Munich, Everton, LA Galaxy, Club Leon
UCL apps: 2

One of U.S. soccer's most celebrated players, Landon Donovan dabbled in the Champions League in his final season at Leverkusen in 2004/05. The Californian forward made two substitute appearances in Bayer's last-16 showdown with English giants Liverpool, but was unable to effect the outcome as Die Werkself lost 3-1 home and away.

Although Donovan later returned to Germany, spending the 2009 off-season in Munich with Bayern, he wasn't around long enough to be considered for Champions League knock-out ties against Sporting Lisbon (12-1) and Barcelona (1-5). Currently unattached, the former LA Galaxy goal-getter's total tally over the course of his two-club German stay reads 16 competitive appearances, one assist.

Landon Donovan (l.) was part of the Leverkusen side beaten by eventual 2005 Champions League winners Liverpool. © gettyimages / Christof Koepsel/Bongarts/Getty Images

Jovan Kirovski

Age: 42 (retired)
Previous clubs: Manchester United, Borussia Dortmund, Fortuna Cologne, Sporting Lisbon, Crystal Palace, Birmingham City, LA Galaxy, Colorado Rapids, San Jose Earthquakes
UCL apps: 5

Born in California to Macedonian parents, Jovan Kirovski cut his teeth at Manchester United before earning a move to Germany with a Dortmund side that had just claimed the 1995/96 Bundesliga title. The 6'1" forward got his first taste of Champions League football as a substitute in group games with Atletico Madrid, becoming the first U.S. national to appear in the competition, but did not make the squad for the triumphant final against Juventus.

Kirovski etched his name into the archives once again as the first American to play in the UEFA Super Cup a few months later, starting the first leg and making a 17-minute cameo in the return fixture as Dortmund lost 2-0 on aggregate to Barcelona. After making further appearances in the Champions League groups against Parma and Galatasary, the 62-time USA international scored his first and only tournament goal in a 3-0 win over Sparta Prague.

Jovan Kirovski (back row, 3.l.) got his hands on 'Old Big Ears' whilst playing for Dortmund back in 1997. © imago

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