If anyone wants to see the effect of playing youngsters for the sake of it, and indeed to appease the fans when they are not ready or when the team is going through a bad spell have a look at McCrorie , Docherty and Beerman.#
It isn't always just physical, but sometimes Young players need to come in and out of good winning teams who are firing on all cylinders.
The one thing I don't agree with , is that any player is ever too young, a real problem in Scotland is thinking 23 is young.
IMO, A player should have a handful of games by the time they are 19, then be pushing for a first team spot and Ideally played over 100 games by the time they are 22.
In Scotland we have it way way wrong.
The only caveat is , you need to be careful when you bring them in and take them out.
Someone like Kennedy and Dapo are getting brought in and out of the first team training, both have had first team action, it will be a slow process until they are 21/22 then they will either kick on or move on IMO - but we don't want to ruin them.