The Australian and younger sister Narelle Krizek are the top seeds in the women's doubles where they will aim to go one better than their runners-up finish in 2011.

They have received a bye in the first round with England's second seeds Suzie Pierrepont and Tina Rix expected to provide their toughest competition.

Pierrepont won the last edition of the title alongside Carrie Hastings in 2015 and will be hoping for more success this year.

In the mixed doubles competition, McElhinny and Scott Arnold have been named top seeds.

The two sisters will be rivals in this event with Krizek and Matt Jenson listed as second seeds, putting the siblings on collision course for the final.

Canada's reigning champions Stephanie Hewitt and Viktor Berg are competing again and are seeded third.

In the men's event, Michael Ferreira and Jonny Smith of England are top seeds as they eye a first title.

Indians Manek Mathur and Parth Sharma are seeded second, with defending champions Clive Leach and John Russell of England ranked fifth.

Competition will take place at the Racquet Club of St Louis and the Missouri Athletic Club between September 21 and 24.

Hardball squash, which originates in North America, is a different variant of the sport featuring a harder ball and different size courts.