Last year, Victoria Azarenka (34) and Sofia Kenin (25) were the only former women's champions in the draw at Melbourne Park but there will be six when the 2024 tournament kicks off on Sunday as Osaka, Angelique Kerber (35) and Caroline Wozniacki (33) all return.
The returning trio and Azarenka will be accompanied by their children as they look to match the feat achieved by Evonne Goolagong Cawley in 1977 and Kim Clijsters in 2011 by holding aloft the Daphne Akhurst Memorial Cup as mothers.
Although Wozniacki and Kerber have looked competitive since their respective returns, Osaka appears the most likely to be challenging at the business end of the year's first Grand Slam despite more than a year on the sidelines.
Osaka is the youngest of the returning champions and she showed at the Brisbane International she still has the weapons that earned her the 2019 and 2021 Melbourne titles.
More importantly, perhaps, she looked happy to be back in the game, even in defeat, and determined to build on a career which has already earned her four Grand Slam titles.
The bookmakers clearly feel it is too early for Osaka, though, and strongly favour the players who have made a case to be considered a new 'Big Four' of women's tennis since Serena Williams and Ash Barty retired in 2022.
The sixth former champion in the draw is last year's winner Sabalenka, who claimed her first major prize by beating Rybakina in the final on Rod Laver Arena.
The Belarusian reached at least the semi-finals at all four Grand Slams last year - a feat last achieved by Williams in 2016 - and would have finished the year as world number one but for a loss to Swiatek at the WTA Finals.
Four-times Grand Slam champion Swiatek has only once been past the fourth round at Melbourne Park, when she lost in the semi-finals to Danielle Collins (30) in 2022 but proved she can win big prizes on hard courts with her US Open triumph the same year.
QUIET STATEMENT
Former Wimbledon champion Rybakina will be one to avoid as she knocked out Swiatek in the fourth round last year and also ousted her from the semi-finals at Indian Wells.
The big-serving Kazakh made a statement in her own quiet way by routing Sabalenka 6-0, 6-3 in the final of the Brisbane warm-up tournament last week to move up to third in the world rankings ahead of American Gauff.
Gauff first made her mark at Melbourne Park as a 15-year-old when she beat Venus Williams and defending champion Osaka on her way to the fourth round in 2020, a stage she also reached last year.
She has not taken her foot off the pedal since winning her first Grand Slam title at the US Open last year and showed strong form to retain her title in Auckland as she tuned up for her final major as a teenager.
Fellow American Jessica Pegula (29) has reached the quarter-finals for the last three years and leads a chasing pack also featuring Tunisia's Ons Jabeur (29), who has played three Grand Slam finals but never been past the last eight in Melbourne.
Azarenka, the last back-to-back women's champion in 2012 and 2013, always starts the season well and made the semi-finals last year before losing in straight sets to Rybakina.
Another player returning to Grand Slam action after a lengthy absence is Emma Raducanu (21) but the 2021 US Open champion would consider it a triumph to get to the second week after eight months on the sidelines with wrist and ankle issues.
