ok, now not posible to change it xD
so, 2nd thing u have to know, is that try to keep your young players of the academy that have 4-5 stars, because they train very fast...
well... all depends of your budget... maybe you prefeer to buy scout players directly, of 6 stars, and thats all, but, think that every season if you win a level your players will loose a star, so, it can be expansive this game if you buy all, or lots of players every season.... so, try, to keep young players and train this, because if you have the stadium at max. you will have young players every 12 days and that helps a lot.
and there are more things u have to know, just see some threads of this forum, will help you a lot.