How can I tell the end of a player's development in a particular skill during the transfer market?

[eslamkhaled]

If I buy a player from the transfer market, how can I know if he's capable of developing a certain skill to a specific level? I know that in training, when he reaches the limit of his development in a particular skill, he gives a red light, but I want to know before he reaches that point where he will be able to go.