If you need rare players (like 2position AM), then you should try this:
Go to the meesages, tab transfers. Click on message about recently bought player. It doesn't have to be your player, it could also be your friends new player, but important thing is that you and your friend are on same server. Then click on the name of club that sold him. Look for players in his squad. If you're lucky, you could find his sub/reserve as your next important/best player. Send him offer.
Add this manager as a friend so you could buy his players in future.
Also you can do opposite, add manager who bought your player. I have friends that already bought few players from me.