Melbourne - Marc Leishman will partner Cameron Smith for the home team when Australia hosts the World Cup of Golf at Metropolitan Golf Club in November.
Tournament officials said on Friday that Jason Day was not available for Australia due to the pending birth of his child, and that Leishman, as captain, chose Smith over Adam Scott to play alongside him in the 56-man, $7 million tournament from November 22-25.
Officials said the USA team would be Kyle Stanley and Matt Kuchar, who won the 2011 World Cup title with then-partner Gary Woodland.
Defending World Cup of Golf champions Denmark are set to return, with Thorbjorn Olesen a committed starter. Olesen partnered Soren Kjeldsen to capture a four-shot win in 2016 and has until next Thursday to confirm his playing partner for a title defence in November.
Spots in the World Cup field go to the highest-ranked available players from the top 28 nations.
Australia has won the World Cup five times, with Scott and Day the most recent winners in 2013 at Royal Melbourne with Leishman and Scott finishing tied for ninth at Kingston Heath in 2016.
Leishman and South Africa's Branden Grace are among a group of five players who competed on the International Team at the 2017 Presidents Cup.
Argentina's Emiliano Grillo, Canada's Adam Hadwin and Venezuela's Jhonattan Vegas are the others.
Grace has yet to confirm who his partner will be.