Australia may not know its 2018 World Cup fate until the morning after their must-win clash against Thailand.
Thailand's King's Cup victory highlighted a new-found defensive strength that will make Australia think ahead of September's World Cup qualifier.
Southeast Asian champions Thailand retained the King's Cup after defeating Belarus 5-4 on penalties in Sunday night's final in Bangkok.
Football Federation Australia said on Saturday that the Socceroos will play Thailand at Melbourne's AAMI Park on Sept. 5 in their final WCQ game.
Son Heung-Min and Ki Sung-Yeung could miss the start of the new Premier League season, and South Korea's two remaining 2018 World Cup qualifiers.
Malaysia remain two spots ahead of Singapore in the FIFA rankings after both fell 12 places, with minnows Myanmar and Bhutan now above both of them.