Gunner89 it is highly unusual for a 16 year old to play regularly in any position. Even then, if you look at regularly played 17 year olds in the past decade, only one is a CB (Cubarsi). and the list of others is not very long - Bellingham, Pedri, Lamine, Zaire-Emery, Donnaruma. Gavi. You can also include De Ligt, Hato, Camavinga at smaller clubs