Youth camp

Real world clubs have youth camps for 2 main reasons:
1) having players for the future
2) make money
the game provides the first reason but what's no2? clubs train kids and when they are ready, they sell them and make money.
my suggestion is; youth camp should have capacity for example 3,5,8 or whatever youth players. if managers don't want to sign youth players, they can save them in youth camp and sell them in auction and make money. if the capacity of youth camp is full, the must either sign or release them.

There must be different squad of U21 or that is impossible

This is not real world game so Dont take it seroius😁