Aryna Sabalenka will return to the Brisbane International before the world tennis No.2 shoots for a third straight Australian Open title.
The two-time defending champion at Melbourne Park and reigning US Open winner was runner-up at Pat Rafter Arena earlier this year.
On Wednesday she was confirmed, alongside women's world No.4 Jessica Pegula and men's duo Holger Rune and Frances Tiafoe as the first four players locked in for the event that begins on December 29.
Pegula, beaten in the New York final by Sabalenka this year, has never played the Brisbane International.
Rune was runner-up this year, and Tiafoe hasn't featured since 2018.
Tournament organisers remain hopeful of luring former champion Nick Kyrgios to the event after he confirmed his intent to return from long-term injury for the Australian summer.