I've always noticed that these categories are not just affected by players bought and sold, but even by bids and transfer listings that do not result in a transaction. Last week, when I was bidding on players before finally landing one, I was getting 5 balls for doing everything I could to improve the team. Yesterday I noticed I was down to one ball on the fear that my star players will be transferred when I had a couple of star player in the TL (the deadline for sales is today, and it looks like one of them will be sold, though neither was sold before today). Granted I did sell a rookie a couple of days ago, but still, that last time I put a star player up for sale I recall the the number of balls dropping to one the day after I listed him.
I could be wrong on this, so confirmation about this from another poster would be good.
Don't ask what sort of Chunks they are, you probably don't want to know. Blowing Chunks since Season 4!