The Australian Open, the first tennis Grand Slam of the year, will kick off at Melbourne Park next Monday.

Here are five talking points, from Novak Djokovic's return following his dramatic deportation last year to the battle to deny Iga Swiatek:

What reception will Djokovic get?

The nine-time Australian Open champion is back in Melbourne having been deported on the eve of last year's tournament because of his Covid vaccination status.

Novak Djokovic of Serbia attends a practice session ahead of the Australian Open tennis tournament in Melbourne on January 14, 2022. (Photo: AFP)

He has admitted to feeling nervous about what sort of reception he may get from spectators, but early signs suggest it will be positive.

When he played a doubles match in Adelaide at the start of this month -- his first match in Australia in almost two years -- he was given a raucous welcome.

His rivals also appear to be happy for him to be back at the Australian Open, with Rafael Nadal saying: "Novak is here, good for tennis, good for probably the fans."

Is Nadal on the slide?

Rafael Nadal's breathtaking career has been defined by an unrivalled fighting spirit, with the Spanish great finding a way back from regular injuries to reclaim his spot at the top of men's tennis.

Spain's Rafael Nadal hits a return during a training session ahead of the Australian Open tennis tournament in Melbourne on January 7, 2023. (Photo: AFP)

His victory at the Australia Open last year was a record 21st Grand Slam title and he also went on to win the French Open title.

But now 36, Nadal has lost six of his past seven matches stretching back to his last-16 defeat at the US Open, casting fresh debate about whether he is on a downward spiral.

An early exit in his title defence would raise more questions.

Who can challenge Swiatek?

Swiatek dominated women's tennis in 2022, winning the French and US Opens and topping the rankings following the retirement of 2021 Melbourne Park champion Ashleigh Barty.

Poland's Iga Swiatek hits a return against Switzerland's Belinda Bencic during their women's singles match at the United Cup tennis tournament in Brisbane on January 2, 2023. (Photo: AFP)

The Pole will be hot favourite to win the Australian Open for the first time but showed some vulnerability in a loss to third-ranked Jessica Pegula at the recent United Cup.

With the great Serena Williams also retired, second-ranked Ons Jabeur and Coco Gauff could also be challengers.

The American Gauff lost to Swiatek in the French Open final but at 18 she is improving all the time and triumphed in Auckland on Sunday for the third WTA title of her career.

Big-hitting Belarusian Aryna Sabalenka also looks in good form after winning the Adelaide title last week.

Which Kyrgios will show up?

The home fans no longer have Barty to cheer, putting more focus on unpredictable Wimbledon finalist Nick Kyrgios.

Australia's Nick Kyrgios plays the ball to Bulgaria's Grigor Dimitrov during their 2022 World Tennis League exhibition match at Dubai’s Coca-Cola arena in the United Arab Emirates, on December 21, 2022. (Photo: AFP)

There has never been any doubt about the 27-year-old's talent but he has often been let down by his temperament.

There were several fiery flashes on his run to the final at Wimbledon -- easily his best performance at a Grand Slam -- before going down to Djokovic in four sets.

His build-up to Melbourne has been disrupted by an ankle injury and he pulled out of a warm-up tournament in Adelaide.

He is however expected to play the Grand Slam -- watch for fireworks.

Where are the stars?

Retirements and injuries have deprived the Australian Open of a slew of big names. Barty, Serena Williams and Roger Federer all retired last year.

Men's world number one Carlos Alcaraz, the heir to Nadal, pulled out injured last week. And in a further blow, two-time Melbourne champion Naomi Osaka then withdrew, without saying why.

Spain's Carlos Alcaraz Garfia returns the ball during the men's singles round of 8 tennis match between Spain's Carlos Alcaraz Garfia and Bulgaria's Grigor Dimitrov on day four of the ATP World Tour Masters 1000 - Paris Masters (Paris Bercy) - indoor tennis tournament at The AccorHotels Arena in Paris on November 3, 2022. (Photo: AFP)

The 42-year-old Venus Williams, who has won seven majors, was given a wildcard but she last week also pulled out injured.

Simona Halep, a former Australian Open finalist and two-time Grand Slam champion, is out after failing a drugs test.

It all leaves an opportunity for a new star to emerge.