You need understand following:

Soccer is specified "foot-ball" !-But football in America sometimes is not really "foot-ball ", because they have a game which they call football but play with their hands (Handball ).
Ameriacan is only  country that calls "foot-ball" soccer！

I understand author calls this coin to "Soccer-coin“, beacuse it is only use foot to play foot-ball game. Can't be Handball!