Eriksen moved from Odense to Ajay illustrious youth academy at the age of 16. The versatile midfielder was immediately considered to be one of the most promising youngsters around at Ajax and scored plenty of goals in both the under-16 (B1) and the under-18 (A1). Eriksen was promoted to the senior Ajax side during the 2009-2010 campaign and made his official debut in the 1-1 away draw against NAC.
Few weeks after his 18th birthdaty, Eriksen made his international debut for Denmark in the friendly away to Austria. He made lasting impression among those that sees him play. He can run deep and shoots well with both feet. He nearly scored from a long distance in the game against Japan in the last group game of the World Cup 2010 where Denmark were trailing Japan 0-2. He is also a strong dribbler and has the ability to twist and turn past his opponent with his rapid movements and blessed with great vision. He is considered to be one of the biggest talents Danish football has produced in a generation.