The world's tennis elite have arrived in Melbourne for the first Grand Slam of the year, and the buzz around the Australian Open is already palpable. Starting this Sunday, the tournament promises thrilling action, with finals weekend set for January 25-26.

Here are five major storylines to keep an eye on as Jannik Sinner and Aryna Sabalenka prepare to defend their titles.

Can Steely Sinner Stay Focused Amid Doping Drama?

How does one follow a near-perfect season? That’s the challenge Jannik Sinner faces in 2025.

The 23-year-old Italian returns to Melbourne Park as the reigning men’s champion and world number one, following a stellar 2024 in which he won 73 out of 79 matches, claimed the US Open, ATP Finals, and five other titles, and led Italy to the Davis Cup crown.

But his title defense comes under the shadow of controversy. Cleared of wrongdoing after two failed doping tests last year, Sinner now faces a renewed challenge as the World Anti-Doping Agency seeks a one-to-two-year ban. The Court of Arbitration for Sport will hear the case in April, leaving an air of uncertainty over his future.

Will the resilient Italian maintain his composure and extend his dominance, or will the external pressures prove too much?

Will Djokovic Add Another Historic Chapter?

Novak Djokovic has made a career of defying expectations, and his latest move has the tennis world talking: Andy Murray is now his coach.

The surprise partnership, revealed in November, adds an intriguing layer to the Serb’s quest for an 11th Australian Open title. At 37, Djokovic remains a force, aiming to claim a record 25th Grand Slam title and surpass Margaret Court as the all-time leader in singles majors.

Despite being seeded seventh, Djokovic’s experience and tactical brilliance make him a serious contender. If he triumphs, he would also become the oldest men’s Grand Slam champion in the Open Era — a milestone that’s well within his reach.

Is 2025 the Year Raducanu Takes Off?

Emma Raducanu’s journey since her astonishing 2021 US Open victory has been marked by ups and downs. After battling injuries and the pressures of fame, the 22-year-old is looking to reset her career.

Signs of progress emerged last year as she returned from wrist and ankle surgeries. She has since committed to a full-time fitness program, signaling her determination to become the athlete she envisions. However, a back injury forced her to withdraw from Auckland’s season-opener, leaving her without competitive matches since November.

The question now is whether Raducanu can harness her potential and silence critics. A deep run in Melbourne could provide the boost she needs to regain her footing on the WTA Tour.

Can Anyone Stop Sabalenka’s Hat-Trick?

Aryna Sabalenka has been a dominant force on hard courts, and her record in Melbourne speaks for itself. The 26-year-old Belarusian is chasing her third consecutive Australian Open title, a feat not achieved since Martina Hingis’ three-peat from 1997 to 1999.

Fresh off a year-end world number one ranking and a US Open win, Sabalenka’s powerful, aggressive game is perfectly suited to the fast courts Down Under. She’s won 27 of her last 28 matches in Australia and warmed up with another title in Brisbane.

If her form continues, Sabalenka’s dominance could make her unstoppable as she seeks to etch her name further into tennis history.

How Will Kyrgios Shape Up?

Nick Kyrgios, ever the enigma, returns to the Australian Open stage after a two-year battle with injuries. The 29-year-old’s struggles, particularly with a debilitating wrist issue, had cast doubt on his future in the sport.

His doubles comeback with Novak Djokovic in Brisbane and a valiant singles effort against Giovanni Mpetshi Perricard signaled flashes of his brilliance. However, Kyrgios admitted post-match that his wrist remains a concern, raising questions about his readiness for the grueling demands of a Grand Slam.

Love him or loathe him, Kyrgios’ presence guarantees entertainment. The home crowd will undoubtedly rally behind him, creating an electrifying atmosphere whenever he steps onto the court.

As the Australian Open 2025 gets underway, these storylines promise to make this year’s tournament one to remember. Will new champions rise, or will the defending titans hold their ground? The answers await on the courts of Melbourne Park.