skills of a player

Hello everyone.
My name's José María. Excuse me for my bad english.
I'm level 4 and I have a problem. A few weeks ago I bought a player for 19 years rather expensive (for my budget). However, when I train the player or play a game gets the same points as if he were 28 or 29 years ... FEW ...
Why is this happening? Could anyone give me a solution?
Thank you very much.

Not every young player have the same growth rate... That player is Youth Academy free token player from higher levels... Their growth is much slower than players from Youth Academy you buy for 12-24 tokens...

Ohhh. Now I understand .. thank you very much for the reply and best regards.