Djokovic's bid for 25th major among storylines heading into Aussie Open

The tennis offseason has come and gone in a blur.

The world's top players have been in Australia and New Zealand for the past few weeks preparing for the year's first major.

Jannik Sinner and Aryna Sabalenka kicked off their breakthrough 2024 campaigns with an Australian Open crown. Will lightning strike twice for the tournament's top seeds?

The duo's respective title defenses are among the storylines to watch Down Under when main-draw action begins Saturday.

Djokovic takes another run at No. 25

Novak Djokovic had a strange 2024 season. The 37-year-old broke Roger Federer's record as the oldest World No. 1 in ATP history and surpassed the Swiss Maestro's mark for the most Grand Slam quarterfinals in men's singles play. He finally completed the career Golden Slam last summer with a thrilling straight-sets victory over Carlos Alcaraz at the Paris Olympics, just two months after undergoing surgery for a torn meniscus. It was also disappointing by Djokovic's standards, as he failed to capture an ATP Tour title for the first time in 19 years and came up short in his quest for the all-time lead in major singles championships.

Djokovic has another chance to win his 25th Grand Slam at the major that's been the kindest to him. The Serbian superstar is 94-9 at the Australian Open with 10 of his 24 major trophies coming at Melbourne Park. He's made the semifinals or better at the Happy Slam in each of his previous five appearances.

But it's clear Djokovic is still searching for answers. The former World No. 1 made the intriguing decision to bring on Andy Murray as his coach, even though the latter has no previous experience. Djokovic is also coming off a surprising 7-6 (6), 6-3 quarterfinals loss to Reilly Opelka at the Brisbane International. Djokovic doesn't have the benefit of a top-two seed this time. He managed to avoid a potential Sinner matchup until the final but was drawn into the same quarter as Alcaraz.

Coco bouncing back

Coco Gauff's last match on the Grand Slam stage was one she'd like to forget. The American concluded a rough summer hard-court stretch with 19 double faults in a round of 16 defeat to Emma Navarro at the US Open. She subsequently parted ways with coach Brad Gilbert and brought in Matt Daly to work alongside Jean-Christophe Faurel. The results were immediate, as Gauff won the China Open in their first tournament together, reached the semifinals in Wuhan a week later, and came out on top at the season-ending WTA Tour Finals.

Gauff rode that momentum into 2025 with five straight-sets wins for Team USA at the United Cup, including a second consecutive victory over rival Iga Swiatek. It's no coincidence that Gauff has righted the ship with Daly aboard. The ex-collegiate tennis player is a renowned grip specialist and has been working with Gauff on changing her extreme western grip. The offseason gave Gauff enough time to fully implement those changes, and she's now reaping the rewards. The 20-year-old's second serve has become more reliable, and opponents can no longer target her forehand side, which has suddenly become a weapon. The sky's the limit now that Gauff seems to have ironed out her biggest weaknesses.

Defending champs look to maintain dominance

Sinner's performance in Australia was a sign of things to come. The 23-year-old won 73 matches, added the US Open to his trophy cabinet, led Italy to a second straight Davis Cup crown, and captured the season-ending ATP Finals. He also went the entire season without a straight-sets loss, joining Roger Federer as the only men to accomplish the feat. The fast courts at Melbourne Park suit Sinner's style of play and will make him an even tougher out. Sinner will continue to face scrutiny after avoiding a suspension for two positive drug tests, but that didn't derail his championship bid in New York last year.

Meanwhile, Sabalenka is looking to become the first woman to three-peat since Martina Hingis in 1999. She's made the second week of the Australian Open in each of her last four appearances and leads all active female players in win percentage at the Happy Slam. Sabalenka put all the pieces together in 2024, outmatching opponents with a mix of finesse and elite power. She's conquered her serving woes and heads into the fortnight fresh off a dominant title run in Brisbane.

Is Osaka turning the corner?

Naomi Osaka's return to the WTA Tour last season didn't go according to plan. The four-time Grand Slam champ struggled to find any consistency, going just 20-16 and advancing no further than the second round at the majors. She parted ways with coach Wim Fissette in September and joined forces with Patrick Mouratoglou, who famously guided Serena Williams to 10 Grand Slam trophies.

Osaka was honest about her long-term future in the sport ahead of her season-opening tournament in Auckland, saying she wouldn't "hang around" tennis if the results didn't match her high expectations. The Japanese star sure played with a sense of urgency in New Zealand, dropping just one set en route to her first tournament final in three years. Osaka showed flashes of her old self, winning free points off her serve and overpowering opponents from the baseline with her forehand.

An abdominal injury forced Osaka to retire from the ASB Classic final after taking the opening set. The 27-year-old is "very optimistic" about her chances of playing at the year's first major. No high seed wants to be drawn against the two-time Australian Open winner, especially with her recent form.

New partnerships try their luck

Djokovic, Gauff, and Osaka aren't the only notable players with new coaches in the fold.

Swiatek added Fissette to her team last October prior to the year-end WTA Finals. The Belgian's credentials are well known even beyond his successful partnership with Osaka. He guided countrywoman Kim Clijsters to three major championships and Angelique Kerber to the 2018 Wimbledon crown.

Goran Ivanisevic joined Elena Rybakina's inner circle less than a year after his decorated five-year run with Djokovic ended. The 2001 winner at the All England Club has a wealth of coaching experience on the ATP Tour but has never worked with a player on the WTA circuit. Ivanisevic was known for his booming serve during his playing days and may be able to further weaponize Rybakina's power.

Hubert Hurkacz made two major splashes in hopes of a major breakthrough, hiring Ivan Lendl and Nicholas Massu. Lendl was instrumental in lifting Murray over the hump, working alongside the Scot for all three Grand Slam titles. Meanwhile, Massu is an Olympic gold medalist and reached as high as No. 9 in the ATP rankings. He coached Dominic Thiem to his lone major title win at the 2020 US Open.

Each player's showing over the next two weeks could determine whether these partnerships continue beyond the Australian Open.