The link that connects an instance of 4 players to a particular game
is called a Match. Different sports have different names for it, in
cricket it is a Test Match, in tennis it is a Match. So use the
terminology that is used in your foosball domain.
All the relevant data for that particular Match will go into that
table, for instance the stadium name, date of the game, whether the
Match was sold out etc. This is in addition to the foreign keys that
connect the other two classes.
You will have this association table with just the foreign keys if
your app does not need any other data mentioned above.