A win against Scotland tonight is the main thing — defeat would spell the end of the World Cup dream.
But to qualify automatically tonight, one of Switzerland (against Wales) or Iceland (in Portugal) would have to lose — or win on penalties.
Both sides are currently ranked above the Girls in Green in terms of results during qualification.
READ MORE: Katie McCabe talks about what World Cup qualification would mean to the nation
If there are wins for Switzerland, Iceland and Ireland, the Girls in Green would have to head to New Zealand in February for an intercontinental play-off.
There, 10 teams will vie for the three remaining spots — with Taiwan, Thailand, Cameroon, Senegal, Haiti, Panama, Chile, Paraguay and Papua New Guinea already in the pot.
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