"If they're good enough, they're old enough," is a famous quote from Sir Matt Busby. His ideas about bringing through young talent form the foundations of Manchester United.
The Busby Babes, with an average of just 22, won league titles and were on the brink of securing European glory before the tragic Munich Air Disaster.
Busby rebuilt his team, again focusing on nurturing young players and allowing them to establish themselves in the first team, and he enjoyed further success. United became the first English team to win the European Cup and added a few more trophies to the club's cabinet too.
This mentality was adopted by Sir Alex Ferguson, and he also enjoyed unimaginable glory as a result. United won the treble in 1998-99, a feat no other English team has ever managed, and he did it with a core of players who had made their way from the academy to the senior squad.
Ryan Giggs, United's current assistant manager, is a product of this philosophy. He made his full debut against Manchester City when he was just 17 and scored the game's deciding goal.
In the few matches he took charge of last season, following the sacking of David Moyes, he gave debuts to two youth team players. James Wilson scored two goals in his first game for United, while Tom Lawrence put in an energetic and brave performance on the wing.
Louis van Gaal is United's manager now, though, but fans should expect a similar approach to what has gone before. Let's not forget that Van Gaal gave debuts to Clarence Seedorf, Thomas Mueller, David Alaba and Andres Iniesta when they were teenagers.
So, of United's current crop, which youngsters should expect to make their debuts next season?