With Manchester United starlet Mason Greenwood becoming the youngest ever player to feature in the UEFA Champions League for the Red Devils, here are the 10 youngest players to have debuted in the sought-after club competition.
Tired of reading? Click through the gallery of images to view the youngest footballers to debut in the UCL
Aged 17 years and 156 days, Greenwood made history for United when he came on as a second-half substitute replacing Ashley Young, to become the youngest ever United player to feature in the Champions League, surpassing a record previously held by Gerard Pique.
Greenwood, who became the 231st academy graduate to play for the first team, enjoyed a memorable debut as Ole Gunnar Solksjaer's side overturned a first-leg two-goal deficit to secure a memorable 3-1 victory and advance to the quarter-finals of the competition.
While the United academy graduate's debut came in one of the most memorable comebacks made by United in the Champions League in recent years, the Englishman does not make the cut for the top ten list of youngest players to debut in the competition.
Known to produce world-class youngsters, Belgian outfit Anderlecht, etched their name into the record books in November 1994 handing Nigerian star Celestine Babayaro, his Champions League debut at only 16 years, 2 months and 25 days.
Croatian international Alen Halilovic appears in second spot on the podium after enjoying a memorable year in 2012.
Touted as his country's finest talent since Ballon d'Or winner Luka Modric, Halilovic became the youngest scorer in Prva Liga history at aged 16 years and 114 days, before adding to his rising star two weeks later - becoming the second youngest ever player to feature in the competition after coming on in a 2-0 loss to PSG.
The final star on the podium is former Anderlecht star Youri Tielemans, who became the youngest ever Belgian to feature in the Champions League, after being handed his debut at age 16 years, 4 months and 6 days.
Other players that form part of the list which can be seen on Transfermarkt include a Juventus star, who became the first player born in the 2000s to feature in Europe's five top leagues and the Champions League – click through the gallery above to view the ten youngest players to make their Champions League debuts.
Who is your favourite player on the abovementioned list of names? Let us know in the comments section below.