Every season, there are names that seem to crop up out of the blue and players that take the spotlight having appeared seemingly out of nowhere. Yet, for those who look closely, there are always indicators of players who seem to be on the cusp of making the move from youth level football to the first teams.
Last season saw the likes of Ajax's Matthijs de Ligt take centre stage as the Dutch champions beat Real Madrid and Juventus to make it as far as the Champions League semi-finals. The big defender scored 7 goals and made 4 assists in Ajax's 2018/19 season - an impressive tally for a 19-year-old centre-back.
It wasn't 20-year-old Trent Alexander-Arnold's breakout season but it saw him reach new heights in Liverpool's Champions League-winning campaign and missing out on the Premier League by a hair's breadth. The right-back made 16 assists for the Reds and is a starter for the national side.
As followers of different leagues you often come across players who stand out as youngsters, they mostly tend to be midfielders or attackers. Young defenders are often treated with a high level of caution as errors and miscalculations in defence tend to end in conceded goals.
Defenders usually fully come into their responsibilities and mature as players much later in their career, but we're seeing defensive talent being spotted much earlier now and being given chances as fully mature defenders seem to be knocking on the door at the €100 million club with every transfer that is made.
There have been plenty across Europe who're worth a shout out, however, let's take a closer look at some of the best prospects under the age of 20.