At grassroots level, players sometimes get placed in positions based on their physical makeup – the fast kid is a winger or striker, the slow kid is a defender or goalkeeper, and so on. At a young age, if you label a player as a defender then what’s the problem? Well, placing young players into positions too early might only expose them to the technical qualities required for that one position instead of giving them a more rounded football education and experience that is only gained from playing many different positions.
If an 8-year-old starts out as a defender and plays there for three years, then think about the experience she is gaining by just playing that position. She will probably play the majority of the game facing the play. If this is the case, then how can we expect this player to learn how to play with their back to goal, or tight to the touchline, or in the chaos of midfield?
Also, only playing this position means that she will likely have a defensive partner with whom they have to defend against one striker and perhaps a runner from midfield. So, how many times will she defend in a 1v1 or a 1v2 situation (or similar)? These 1v1s happen all the time across midfield in the 7aside game and a 7aside striker usually has to defend in a 1v2 situation lots of times.
A similar argument can be made for only playing youth players on their strongest side, and how that can sometimes compound the error of only playing them in one position. Going back to our 8-year-old, if they are a right footed defender and only ever play on the right, then how many touches of the ball are they getting with their weak foot? Far fewer than if this player was placed on the left-hand side to help them develop their other foot to a level where it can be used in games.