The meaning of dispossessed in football is "lost balls".
When the football game is dispossessed of footballs it just means they have lost footballs and been deprived of the footballs.
Dispossessed means to be deprived of something or property.
The word dispossession means to deprive someone of property or land and take away the possession of that land or property.
Possession means to own something such as land, property, TV etc while the dispossession means to take away that persons property and possession and so they no longer possess and own that property or land.
An example on how to use dispossession in a sentence would be the dispossession of our house and property by the county due to non payment of property tax means we will have to move out and likely be homeless.
Or the county dispossessed the family of their property and now that the families home and property were dispossessed the family will now be homeless if they cannot find another home to rent or find shelter.
Other good ways and examples on how to use dispossession or dispossessed in a sentence are.
The Gracious Family still enjoyed the royal favor and Jonathan made no attempt to dispossess them.
The government dispossessed the landlords of their property.
In order to pay for the loan on a note, the bank decided to dispossess the family of their car.