Novak Djokovic plays a backhand during practice on December 28, 2022 in Adelaide, Australia. Photo: VCG

Novak Djokovic and Rafael Nadal kick-start their 2023 campaigns this week in Adelaide and Sydney respectively, with the superstar veterans and great rivals eyeing up yet more Australian Open glory.

With the pair sharing 43 Grand Slam titles between them - Djokovic has 21 and Nadal 22 - the scene is set for an epic showdown at Melbourne Park in January. 

Nadal is the defending Australian Open champion and Djokovic is a nine-time winner.

Djokovic returns Down Under for the first time since being sensationally detained and then deported ahead of the 2022 Australian Open because of his refusal to get vaccinated for COVID-19.

He starts his bid for an incredible 10th Australian Open title at the Adelaide International from Sunday, following a troubled and truncated year in which he missed two majors because of his vaccine status.

Djokovic was initially barred from entering Australia before 2025, but a new government in Canberra reversed the ruling and he is now gunning for more silverware at his most successful Grand Slam venue.

He will face a top-notch field in ­Adelaide, including Felix Auger-­Aliassime, Daniil Medvedev and Andrey Rublev, ranked six, seven and eight respectively.

In Djokovic's absence in 2022, Spanish great Nadal swept past Medvedev to win the Australian Open in an epic five-setter - then backed it up with a 14th French Open.

'Good for tennis' 

A "highly motivated" Nadal welcomed rival Djokovic's ­much-anticipated return to the ­Australian Open as "good for tennis" on Wednesday, while brushing off ­suggestions this may be his last tilt at the season-opening Grand Slam.

The 36-year-old Spanish great, who recently became a father, is beginning his new season at the United Cup, a new mixed-team event starting Thursday in Sydney, Brisbane and Perth.

It will provide a warm-up for his defense of the Australian Open title at Melbourne Park.

Rafael Nadal returns the ball during a practice session on December 28, 2022 in Sydney, Australia. Photo: IC

Nadal said he was happy to see his superstar rival back.

"Novak is here, good for ­tennis, good for probably the fans," the world No.2 said in Sydney. 

"Let's see, no? Best ­players on court always win."

Nadal backed up his Australian Open win in 2022 with a 14th French Open but struggled with injury after withdrawing from the Wimbledon semifinal with an abdominal tear in July.

Despite a poor second half of the year, Nadal said he was raring to go again with a clash first up at the United Cup against British world No.14 ­Cameron Norrie.

"The highest motivation to try to start well. It's always important to start well for me, for the confidence," Nadal said. "The last few months haven't been easy for me. Main thing for me now is recover the positive feelings on court, being competitive." 

Eighteen countries will compete in the United Cup across 11 days from Thursday, with Brisbane, Perth and Sydney hosting group games in a round-robin format.

Ties comprise two men's and two women's singles matches and one mixed doubles. The finals ­series will be played in Sydney.

World No.3 Casper Ruud and Germany's Alexander Zverev, who is returning from a serious ankle injury, will participate.

'A lot of hours on court'

Top-ranked Carlos Alcaraz will warm up at the Kooyong Classic exhibition in Melbourne from January 10 to 12 as he battles back from the abdominal injury that shortened his preseason training block.

The 19-year-old Spaniard, a major threat to Djokovic and Nadal, missed the season-ending ATP Finals and ­Davis Cup Finals with a muscle tear, but is confident he will be ready.

"I would say the key is to practice a lot, spend a lot of hours on court," he said earlier in December.

Italy's Jannik Sinner and world No.9 Taylor Fritz, among others, will also use Kooyong to fine-tune. 

Women's world No.1 Iga Swiatek will acclimatize in Perth with her Polish teammates at the United Cup on the back of winning the French Open and US Open in 2022.

The three-time Grand Slam champion is targeting a first Australian Open title after losing in the 2022 semis to Danielle Collins, who then crashed to Ashleigh Barty in the final.

Swiatek inherited the top ranking following the shock retirement of Barty in March, and has been dominant ever since.

American world No.3 Jessica Pegula and resurgent French world No.4 Caroline Garcia, fresh from beating Aryna Sabalenka to win the WTA Finals, also feature at the United Cup.

Four of the other top 10 women begin the year in Adelaide, with second-ranked Ons Jabeur, world No.5 Sabalenka, world No.8 Daria Kasatkina and world No.9 Veronika Kudermetova all entered.