All-rounder Glenn Maxwell, who hasn't played international cricket for Australia since last October, made the cut to the list, while seasoned campaigners Peter Handscomb, Shaun Marsh and Nathan Coulter-Nile all have been overlooked.
Both Cricket Australia and the England & Wales Cricket Board have been engaging with each other over the possibility of staging a limited-overs series in the UK in September.
Acknowledging there remain several hurdles to overcome, Cricket Australia's Executive General Manager of National Teams, Ben Oliver, noted the organisation's determination to do whatever is necessary to be ready.
Oliver said: "The ECB are a long-standing and valued international cricket partner and we are doing all we can to give the tour the best possible chance of taking place.
"We continue to work with the ECB and government agencies and a decision on the tour will be made in due course.
"In the meantime, the identification of a preliminary list will enable us to work with players and states more directly on the preparation for the tour in the hope it can proceed.
"The health and wellbeing of players and staff, along with our commitment to public health within our communities, remain our utmost priority," he added.
National Selector Trevor Hohns said: "This preliminary list covers the contingencies of playing One-Day Internationals and T20 Internationals in bio-secure hubs with the likely prospect of not being able to bring in replacements should the tour proceed.
"The preliminary list also has a view towards the upcoming ICC T20 World Cup and in the longer term the 2023 ICC World Cup," he added.
Australia's preliminary squad: Sean Abbott, Ashton Agar, Alex Carey, Pat Cummins, Aaron Finch, Josh Hazlewood, Travis Head, Usman Khawaja, Marnus Labuschagne, Nathan Lyon, Mitchell Marsh, Glenn Maxwell, Ben McDermott, Riley Meredith, Michael Neser, Josh Philippe, Daniel Sams, D'Arcy Short, Kane Richardson, Steven Smith, Mitchell Starc, Marcus Stoinis, Andrew Tye, Matthew Wade, David Warner, Adam Zampa.