Capacity Space is measured by the amount of money left on your team's money left over. For example, if you have 800 Thousand dollars left and you are trying to get a player that demands 3 Million Dollars, then you don't have enough. OR if you are trading another team, and you only have 800 Thousand left, and you choose a high-rated player, then the message in your PDA will state that your team has no Cap. Space. So, if you want to increase Cap. Space, you will have to either release players or trade for lower-rated players.