Not sure if this has been posted but when a player asks to be transfer listed - just say NO! Instead of them standing firm after you say that you want the club to match their ambitions. I got really mad when another player of mine wanted to leave after my two star CB's decided they wanted to leave ( i told them I wanted them to progress with the clubs and then threw a strop and wanted to be sold for peanuts) but the last guy - i hit No you arent leaving and he withdrew his request.
I've only really had this happen with players who wanted first team football and they weren't in my first team because they weren't good enough so... Can you find your own way out or do you need directions?
If a player wants to leave I tend to let it happen as long as I think I can get their value in a transfer fee. It only ends up affecting squad harmony and results eventually so I just get rid. Often those players aren't the kinds of players I want in my team anyway.