Ok, so maybe will be good, too, to see how difficult is, if we buy a "bad" player, to convert it in a "effective" player.... For example, I waste 50 tokens in one ST, I waste another token, to change the name to Djibril Cissé... and yeah I convert this guy in a French guy from París... xD

I can say, in this case, and others, that the player is "programmed" to have bad statics, so, maybe is possible to see in only 4-5 matches using a player, if the better option is sell this guy...

I've a 2nd case, with my MC Edgar Davids, (have nationality of Surinam, don't know if this affects..) but, this player is effective when have the attack skills at 5* level, and, usually, do the same action in the matches. When you don't expect, he do a shoot, (from far away) and, scores.
This is my 2nd month of training in the level 10, and I managed to recover his effectiveness, and, yesterday he scores a goal.

So, maybe noob players will read this post, and in my case, I've to say that, if you have a ST that don't scores in 4 matches, just, buy him, because for sure, is programmed to have this bad statics all his career...
If you found one that scores 3 goals in the 1st match, keep it.