Rafael Nadal returns from a "winding, tortuous" injury journey in Brisbane this week, while fellow superstar Novak Djokovic kickstarts his bid for an unprecedented 11th Australian Open title at Perth.
It appeared last season that the veterans, with 46 Grand Slam crowns between them, may never share a competitive court again.
But the prospect is back in play with Spain's Nadal recovering from hip surgeries that sidelined him for almost a year.
He begins what is set to be a farewell season at the Brisbane International from December 31-January 7 alongside Andy Murray and world number eight Holger Rune.
Top-ranked Djokovic has opted for the mixed teams United Cup in Perth and Sydney, starting Friday, as have fellow top 10 players Stefanos Tsitsipas, Alexander Zverev and Taylor Fritz.
Barring last-minute setbacks, Nadal and Djokovic will then grace the courts of Melbourne Park for the Australian Open from January 14, perhaps for the last time together.
The 22-time Grand Slam tournament winner Nadal has not played since a second-round loss to American Mackenzie McDonald at the Australian Open this year, leading to what coach Carlos Moya said was "a winding, tortuous road, with many curves".
Now 37, Nadal said he expects "nothing" from himself this time around.
"I have internalised what I have had throughout my life, which is demand myself the maximum," he said in announcing his return.
"Right now what I really hope is to be able not to do that, to accept things are going to be very difficult at the beginning and give myself the necessary time."
Since being sidelined, Nadal has been overtaken in the total number of Grand Slam tournaments won by his Serbian arch-rival, who is targeting an all-time record 25th major title in Melbourne.
The 36-year-old Djokovic won three Grand Slams in 2023, but ended the season with two losses to burgeoning Italian Jannik Sinner at the Davis Cup.
Spanish world number two Carlos Alcaraz also notched a sensational win over Djokovic in the Wimbledon final.
The fourth-ranked Sinner gets his season under way at the Kooyong Classic exhibition event in Melbourne, while Alcaraz has nothing currently scheduled before the Australian Open.
- Nervous Naomi -
Four-time Grand Slam champion Naomi Osaka also makes her highly anticipated return in Brisbane, having not played since September 2022.
The Japanese star, who gave birth to daughter Shai in July and has previously struggled with her mental health, admitted she was "nervous" but "excited".
"I definitely want to win more Grand Slams," she said.
Like Djokovic, women's world number one and four-time Grand Slam winner Iga Swiatek will acclimatise in Perth with her Polish teammates at the United Cup.
The French Open champion briefly surrendered her top ranking to Aryna Sabalenka during 2023 but reclaimed it with a gutsy triumph at the WTA Finals in Cancun.
"It was certainly a demanding season that taught me a lot and which makes me even more proud," said Swiatek, an Australian Open semi-finalist in 2023.
Sabalenka is also a starter at Brisbane in a stacked field featuring eight of the world's top 20 women as she looks to build on a sensational year, kickstarted by winning her maiden Slam at Melbourne Park.
"It's a tournament that's attracted so many good players in the past and I'm hoping it will set me up for another successful summer," said the Belarusian world number two of the Brisbane event.
Fourth-ranked Elena Rybakina, who Sabalenka beat to win the Australian Open title, is another in Brisbane.
World number three Coco Gauff defends her Auckland Classic title from January 1, after a breakthrough season for the 19-year-old that saw her claim her first Grand Slam at the US Open.
She is joined in New Zealand by Elina Svitolina and Caroline Wozniacki as they continue their comebacks from maternity leave, while former US Open champion Emma Raducanu returns from multiple ankle and wrist surgeries.