Albert Gudmundsson, Iceland
Gudmundsson turned 21 the day after the World Cup started. He has made an impressive start to his senior Iceland career, scoring three goals from his five caps so far.
Amine Harit, Morocco
After playing for France at youth level, Harit changed allegiances to represent Morocco and has three caps so far after making his debut in October 2017.
Bassem Srarfi, Tunisia
20 year old Bassem Srarfi made his Tunisia debut in March this year.
Rodrigo Bentancur, Uruguay
Rodrigo Bentancur turns 21 during the World Cup but has already been capped six times by Uruguay after making his debut last September.
Kasper Dolberg, Denmark
20 year old Dolberg has so far been capped four times by Denmark.
Nikola Milenkovic, Serbia
Since earning his first senior cap for Serbia in 2016, Fiorentina’s 20 year old centreback, Milenkovic has featured three times for the national team.
Hamza Mendyl, Morocco
20 year old left-back Hamza Mendyl, who plays for French side Lille, has already been capped 13 times by Morocco after making his debut in an African Cup of Nations qualifier in April 2016.
Edson Alvarez, Mexico
Edson Alvarez plays for Mexican side Club América and the defender has also been capped 11 times by Mexico. He got his debut goal in the Gold Cup against Curaçao when he became the youngest Mexican player to ever score in the tournament.
Marcus Rashford, England
20-year-old Rashford is one of England’s most exciting players.
Luka Jovic, Serbia
Last summer, 20 year old striker Jovic signed on at Eintracht Frankfurt on a two-year-loan from Benfica.
Lee Seung-woo, South Korea
The 20-year-old made 14 league appearances for Verona in his debut season as they were relegated to Serie B.
Ismaïla Sarr, Senegal
The 20 year old winger has made 24 league appearances during his debut season for Rennes and he has scored five goals.
Ian Smith, Costa Rica
The 20 year old right-back plays for Swedish side IFK Norrkoping and came on as a late substitute for Costa Rica against England as his side were defeated 2-0 in a pre-world cup friendly.
Jose Luis Rodriguez, Panama
The midfielder turns 20 tomorrow (19 June) but was capped twice by the Panama senior team before being included in their World Cup squad.
Moussa Wague, Senegal
Still just 19, the right-back plies his trade for Belgium side Eupen and has made 28 appearances in all competitions this season.
Trent Alexander-Arnold, England
20 in October, Alexander-Arnold has had a tremendous breakout campaign for Liverpool this season, making himself the first-choice right-back at Anfield.
Francis Uzoho, Nigeria
19-year-old goalkeeper Uzoho, made his senior debut for Deportivo while he was 18 and becoming the youngest ever foreign goalkeeper to debut in La Liga.
Achraf Hakimi, Morocco
The 19-year-old Moroccan full-back became Dani Carvajal’s back-up this season and has made nine league appearances.
Kylian Mbappe, France
Mbappe rose to prominence breaking into the first team at Monaco at the age of 16 and he soon asserted himself as one of the most promising young players in world football.
Daniel Arzani, Australia
The attacking midfielder is the only player born in 1999 to play at this year’s World Cup but has already been capped twice by Australia and scored his first senior goal recently against Hungary.