World number four Karolina Pliskova has withdrawn from the upcoming Australian Open, succumbing to a hand injury.

Pliskova – a two-time grand slam runner-up and 2019 Australian Open semi-finalist – hurt her hand in a practice session.

The 16-time WTA Tour champion will miss the main draw of the year's opening slam event, which gets underway on January 17, for the first time since failing to progress beyond qualifying in 2012.

"Unfortunately I hurt my right hand in practice yesterday and I won't be able to play in Adelaide, Sydney and Australian Open this year," Czech star Pliskova said.

"I am sad not being able to start my season in Australia and I will miss my Australian fans very much."

Australian Open officials also confirmed Pliskova's absence on Thursday.

"You will be missed, @KaPliskova. Wishing you a speedy recovery," the Australian Open wrote via social media.

Pliskova lost in the Australian Open third round at Melbourne Park earlier this year before falling at the second hurdle at the French Open.

The 29-year-old then reached the Wimbledon decider, trumped by world number one Ash Barty, followed by a quarter-final appearance at the US Open.

Dominic Thiem's comeback has been further delayed as the 2020 US Open champion does not feel ready to return at this week's Mubadala World Tennis Championship.

Austrian star Thiem has been out of action since suffering a wrist injury at the Mallorca Championships in June.

The 28-year-old missed Wimbledon and was unable to defend his title at Flushing Meadows, but he appeared to be on course to make his comeback before the end of 2021 after revealing in October he does not require surgery on his wrist.

However, the world number 15 is now facing a battle to be back to full fitness for January's Australian Open after withdrawing from an exhibition event in Abu Dhabi.

"I was looking forward to making my return to competition at Abu Dhabi but I feel that I am not yet ready to compete at the highest level," the 17-time ATP Tour champion posted via Twitter on Tuesday.

"It's disappointing to not take part this year but I need to continue my preparation for the upcoming season."

Thiem follows Casper Ruud in pulling out of the tournament, which begins on Thursday, while Emma Raducanu is out of the women's singles after testing positive for coronavirus.

Dan Evans and Taylor Fritz have taken the places of former world number three Thiem and Ruud, joining Andrey Rublev, Denis Shapovalov, Andy Murray and defending champion Rafael Nadal in the draw.

Rafael Nadal is set to start his 2022 season at the Melbourne ATP 250 ahead of the Australian Open.

Nadal this week appeared on the entry list for the first grand slam of the year, which begins on January 17.

The Spaniard has not featured on the ATP Tour since August, when he lost against Lloyd Harris at the Citi Open in Washington D.C.

But Nadal is going to be back into the swing of things in the next month. The Melbourne 250 starts on January 4 and will serve as a warm-up for the Australian Open.

Gael Monfils is headlining the ATP 250 event in Adelaide during the same week, while Novak Djokovic – whose participation at the Australian Open is as of yet unclear, although he is also listed for entry – is set to lead Serbia at the ATP Cup in Sydney. 

Djokovic has not yet revealed his COVID-19 vaccination status. If he is not fully vaccinated, the 34-year-old may not be able to compete in Melbourne, barring a medical exemption.

Nadal has dropped down to world number six after another injury-hit season, in which he won two titles, triumphing in Barcelona and Rome.

He has only won the Australian Open once, in 2009, but has since been beaten four times in the final, in 2012, 2014, 2017 and 2019.

Since the start of the 2020 season, Nadal has played in four finals, winning them all, including last year's delayed French Open.

Serena Williams has withdrawn from the Australian Open as she is not yet ready to make a comeback from injury.

Williams has not played since suffering a torn hamstring at Wimbledon in June.

The 40-year-old stated last month that she was "better" and planned to play in the first grand slam of 2022 at Melbourne Park.

Williams will not go in search of a record-equalling 24th major title next month, though, revealing she is not fit enough to take her place in the draw.

She said in a statement: "Following the advice of my medical team, I have decided to withdraw from this year's Australian Open. While this is never an easy decision to make, I am not where I need to be physically to compete. 

"Melbourne  is one of my favourite cities to visit and I look forward to playing at the AO every year. I will miss seeing the fans but am excited to return and compete at my highest level."

The legendary American's last grand slam triumph came at the Australian Open in 2017.

While Williams will not compete, world number one Ash Barty will participate, as will US Open champion Emma Raducanu and four-time grand slam winner Naomi Osaka.

Novak Djokovic has been included in the official entry list for the 2022 Australian Open, with Tennis Australia adamant that no loopholes are being explored.

The world number one, who has won nine of his 20 grand slam titles in Melbourne, has not yet disclosed his COVID-19 vaccination status, meaning there is doubt over whether he will be able to participate.

Every person competing or attending the grand slam next month will need to have been fully vaccinated against coronavirus.

However, despite the uncertainty, the 34-year-old was named in the official list of players for the tournament draw.

Djokovic had already been named in Serbia's team for the ATP Cup, which is to be held in Sydney, leading to speculation that he could enter Australia by travelling directly to New South Wales, which has different COVID-19 restrictions to the state of Victoria, and may then seek a medical exemption to get around the rules applying to unvaccinated travellers.

James Merlino, Victoria's deputy premier, responded to these reports, which also suggested Djokovic had the backing of Tennis Australia.

"My view on this is really clear and really simple," Merlino said on Wednesday. "Everyone's looking forward to the Australian Open and everyone who will attend – spectators, players, officials, staff – everyone is expected to be fully vaccinated.

"They're the rules. Medical exemptions are just that – it's not a loophole for privileged tennis players. It is a medical exemption in exceptional circumstances if you have an acute medical condition."

Tennis Australia responded to Merlino's comments with a statement of their own.

"Any suggestion that Tennis Australia is seeking 'loopholes' within this process is simply untrue. Adjudicating on medical exemptions is the domain of independent medical experts. We are not in a position to influence this process and nor would we," the statement read.

"Any application for a medical exemption must follow strict government guidelines based on ATAGI (Australian Technical Advisory Group on Immunisation) clinical advice. This is the same process that applies to any person wanting to enter Australia."

While Djokovic's participation is unclear, Serena Williams is a big-name absentee. The 40-year-old, who is one shy of matching Margaret Court's record tally of 23 grand slams, had been expected to play in Melbourne.

Roger Federer had already confirmed his absence, but Rafael Nadal is set to compete for the first time since August.

World number two and US Open champion Daniil Medvedev takes his place in the draw, as does 2020 Australian Open finalist Dominic Thiem.

Australian world number one Ash Barty headlines the women's field, with Naomi Osaka, US Open winner Emma Raducanu and WTA Finals champion Garbine Muguruza also in the draw.

Bianca Andreescu, the 2019 US Open champion, has decided to skip the event to focus on her mental wellbeing.

World number one Novak Djokovic has committed to playing the ATP Cup in Sydney amid ongoing uncertainty over his title defence at next month's Australian Open.

Djokovic has been unwilling to confirm his place at January's Australia Open due to the COVID-19 mandate in Victoria.

The state of Victoria, where the year's opening grand slam takes place at Melbourne Park, has introduced a vaccine mandate for professional athletes and across most industries due to the coronavirus pandemic.

Djokovic's father, Srdjan, said the nine-time Australian Open champion is unlikely to feature in Melbourne unless vaccination rules are relaxed.

But in a boost for the slam's organisers, Djokovic was named in top-seeded Serbia's team for the third edition of the ATP Cup, which will take place in Sydney from January 1-9.

"We're excited to host the third edition of the ATP Cup in Sydney in 2022," said ATP Cup tournament director Tom Larner.

"The playing group enjoy representing their countries and to see 18 of the world’s Top 20 players commit to the event is testament to that.

"The event shows off the passion the playing group have for this format and we look forward to welcoming all 16 teams to Sydney later this month."

The 2021 Australian Open went ahead, albeit in February instead of January, and without fans for most of the tournament following a snap lockdown of Melbourne due to COVID-19.

Djokovic – winner of a joint-record 20 grand slam titles – was among the players critical of the conditions athletes endured prior to this year's Australian Open, with strict quarantine measures introduced.

Bianca Andreescu will miss the 2022 Australian Open to focus on her mental health after suffering a "very challenging" couple of years.

Andreescu has struggled with physical and mental concerns since winning the US Open two years ago.

The 21-year-old has felt the strain even more this year, with her grandmother in intensive care after contracting COVID-19, Andreescu also testing positive and spending significant time in isolation.

The former world number four has decided to skip the first grand slam next year as she takes extra time out to "reset, recover and grow", but vowed to return "stronger than ever."

The Canadian tweeted: "As you all know, the past two years have been very challenging for me for a variety of reasons.

"Especially this year in particular, I spent multiple weeks in isolation quarantining which affected me greatly – both mentally and physically. In addition, my grandmother spent several weeks in the ICU due to a covid infection, something that really hit me hard.

"A lot of days, I did not feel like myself, especially while I was training and/or playing matches. I felt like I was carrying the world on my shoulders.

"I could not detach myself from everything that was going on off the court; was feeling the collective sadness and turmoil around it and it took its toll on me.

"I want to give myself extra time to reset, recover and grow from this (as cliche [sic] as that sounds) and continue to inspire by doing charity work, giving back and working on myself because I know by doing this, I will come back stronger than ever.

"I will therefore not start my season in Australia this year, but will take some additional time to reflect, train and be ready for the upcoming 2022 season."

Novak Djokovic is unlikely to play at the Australian Open in January unless COVID-19 vaccination rules are relaxed, according to the player's father.

Organisers recently confirmed that players must be vaccinated against coronavirus to compete in the tournament, which begins on January 17.

World number one Djokovic, who won a record ninth title in Melbourne last year, has not publicly stated whether he has had the jab.

Srdjan Djokovic told Serbia's TV Prva that being vaccinated is a personal choice, and that Tennis Australia's rules are essentially "blackmail".

"As far as vaccines and non-vaccines are concerned, it is the personal right of each of us whether we will be vaccinated or not," he was quoted as saying by news website B92.

"No one has the right to enter into our intimacy, it is guaranteed by the constitution. Everyone has the right to decide on their health.

"Whether [Novak] is vaccinated or not, that is his exclusive right. Will he publish it, I don't think so. I don't know that decision either, and if I did, I wouldn't share it with you. He has the right to decide as he wants."

When asked about Djokovic's decision to play in Australia, his father added: "Whether he will appear there depends on how [the organisers] position themselves. He would want it with all his heart because he's an athlete, and we would love that too.

"Under these blackmails and conditions, he probably won't. I wouldn't do that. And he's my son, so you decide for yourself."

Djokovic, who is tied on 20 major singles titles with Rafael Nadal and Roger Federer, recently said he was unsure of his participation following his appearance at the ATP Finals in Turin.

"I was just waiting to hear what the news is going to be and now that I know we'll just have to wait and see," he said.

Ash Barty has announced her engagement to Liverpool fan and golfer Garry Kissick, capping a memorable year in style.

Barty added another sparkler to her collection when she revealed an engagement ring on Tuesday, having already landed the glistening Wimbledon trophy and an Olympic medal in the 2021 season.

She posted a picture of herself and Kissick on Instagram, showing off her ring and captioning the shot "Future Husband".

Kissick is a trainee professional at Brookwater Golf Club, a venue close to Brisbane, and is often seen in a Liverpool Football Club shirt, as was the case with the engagement picture.

He and Barty have visited Liverpool's home ground of Anfield together.

Speaking about having the likes of Kissick and coach Craig Tyzzer with her on the road, Barty said during her run to the Wimbledon title in July: "It's nice to be able to share some of these awesome moments with those that put so much time and energy into my career and allow me, encourage me, help me kind of work and figure out a plan and a way that they try and achieve our dreams. I think being able to share that with them is really special."

Barty won a bronze in mixed doubles at Tokyo 2020 alongside long-time friend John Peers, describing that achievement as "a dream come true".

She also won the Yarra Valley Classic, the Stuttgart Open, and WTA 1000 titles at Miami and Cincinnati before calling time on her season after a third-round exit from the US Open, where she lost to Shelby Rogers.

Barty finished the season as world number one for a third successive year, despite her recent inactivity.

She said a major triumph in her homeland was a priority for 2022, saying: "My focus is now on the Australian summer and doing everything I can to win the Australian Open. I can't wait to play at home again."

Australian Open champion Novak Djokovic does not know if he will defend his crown due to the COVID-19 mandate in Victoria.

It remains to be seen whether world number one Djokovic will fly to Melbourne in January amid vaccination requirements.

The state of Victoria, where the year's opening grand slam takes place at Melbourne Park, has introduced a vaccine mandate for professional athletes and across most industries due to the coronavirus pandemic.

As doubts over Djokovic's participation linger, the 34-year-old superstar was asked about his Australian Open plans after losing to Alexander Zverev in the semi-finals of the ATP Finals on Saturday.

"I haven't been talking to [Tennis Australia], to be honest," nine-time Australian Open champion Djokovic told reporters after his 7-6 (7-4) 4-6 6-3 defeat in Turin.

"I was just waiting to hear what the news was going to be. Now that I know, we'll just have to wait and see."

The 2021 Australian Open went ahead, albeit in February instead of January, and without fans for most of the tournament following a snap lockdown of Melbourne due to COVID-19.

Djokovic – winner of a joint-record 20 grand slam titles – was among the players critical of the conditions athletes endured prior to this year's Australian Open, with strict quarantine measures introduced.

Australian Open tournament director Craig Tiley has insisted all players, including Novak Djokovic, must be fully vaccinated against COVID-19 in order to compete at the January grand slam.

Djokovic's vaccination status is unclear, and he has so far refused to confirm whether he has been jabbed, which has led to doubts over whether he will be in Melbourne.

Victorian Premier Daniel Andrews has made it clear that tennis stars arriving for the tournament must be prepared to show proof of having protection against the virus.

For Djokovic, who is competing this week at the ATP Finals in Turin, it remains to be seen whether he is willing to go through that process.

Tiley told Channel Nine: "It's been made very clear, when the Premier announced several weeks ago that in order to participate at the Australian Open, to come into Victoria, you'll need to be fully vaccinated.

"Immediately we communicated that to the playing group, it is the one direction that you take that is going to ensure everyone's safety. All the playing group understands it, our patrons will need to be vaccinated, all the staff working at the Australian Open will need to be vaccinated.

"But when we're in a state where there's more than 90 per cent of the population fully vaccinated, they've done a magnificent job with that, it's the right thing to do."

Tiley said organisers "would love to see Novak" make the trip to a tournament he has won a record nine times.

Djokovic sits on 20 grand slam titles, the same mark as Roger Federer and Rafael Nadal. He needs one more to set the outright men's record, having lost to Daniil Medvedev in the US Open final in September.

"We have been speaking to Novak Djokovic's team and Novak and the team understand clearly that in order to come and play the Australian Open they'll need to be fully vaccinated," Tiley said, according to ABC.

"I know that he wants to play it, he's clearly indicated that and he knows the conditions that he'd have to undergo in order to be eligible to play."

The tournament is due to get under way on January 17, with the player bubbles and quarantine measures that were in force at the 2021 edition no longer in place and Melbourne Park set to operate at full capacity.

Australian player Nick Kyrgios this week said he believes the vaccine mandate is "morally wrong".

The MCG Ashes Test and the Australian Open will be watched by capacity crowds following the easing of coronavirus restrictions in Victoria.

Victorian premier Daniel Andrews has announced there will no longer be limits on gatherings in the state.

Andrews had revealed last month, when the latest lockdown ended, that he was hopeful at least 80,000 will be able to attend the Boxing Day Test.

Australia and England can now look forward to playing in front of a full house of 100,000 next month.

The first grand slam of the year, starting at Melbourne Park on January 17, is also set to be played without a cap on the number of spectators allowed in.

"Whether it's 100,000 people at the MCG on Boxing Day or a smaller group of people standing up at the … local pub, this is the COVID-normal that every Victorian has built," he said at a press conference.

Crowds for the 2021 Australian Open were limited to 30,000 people per day – around half capacity – prior to a snap lockdown being implemented during the tournament.

No more than 30,000 were permitted in the MCG for Australia's Boxing Day Test against India last year.

Roger Federer has confirmed he will not participate at the Australian Open and said he would be "extremely surprised" if he is fit enough to play at Wimbledon.

The 20-time grand slam winner has played just 13 matches in 2021 as he recovers from a third knee surgery in the space of 18 months, with Federer's last appearance a disappointing straight-sets loss to Hubert Hurkacz in the quarter-finals at SW19 in July.

The Swiss great has now officially confirmed he will not be at Melbourne Park for the first grand slam of 2022, while it remains touch-and-go whether Federer will be back at Wimbledon this year.

"At the moment, I expect to be able to return in the summer of 2022," he told Tribune de Geneve having confirmed playing in Australia is out of the question. 

"The next four or five months are crucial. In the spring, I will already see things much more clearly. The truth is that I would be incredibly surprised if I were to play again at Wimbledon [in 2022]."

"When you get right down to it, it doesn't make much difference whether I return in 2022 or not until 2023, at 40 or 41. It doesn't matter. The question is rather will I manage to torture myself again day after day for my comeback?

"My heart says 'yes' today. So, I'm taking things step by step. I have experienced similar challenges many times in my career sometimes without the public being aware of it. Even though I know that the end is near, I want to try to play some big matches again. It won't be easy but I will try."

Now aged 40, Federer's latest injury setback led to suggestions he could call time on his glittering career, though his coach Ivan Ljubicic this week said he was not contemplating such a decision.

Federer accepts he may never play in a grand slam final again and is at peace with that fact, but still "believes in these miracles" as he aims to once again compete among the elite level.

"If I do my rehabilitation intensively, there is a chance that I will get back to a high level," he added. 

"If I do strength training, go on the bike, swim, do balance exercises, work on my upper body, then I believe in it.

"Will I return to the Tour for a smaller round or for something bigger? Nobody knows, neither the doctors nor me. But I'm fighting for it. To be clear, my world will not collapse if I never play another grand slam final.

"But it is my ultimate dream to return once again. And in fact, I still believe in it. I believe in these kinds of miracles. I have already experienced them. 

"Sports history sometimes writes such miracles. I am realistic – it would be a great miracle but there are miracles in sport."

Nick Kyrgios believes the Australian Open should be cancelled as he threw his support behind rival Novak Djokovic, insisting the COVID-19 vaccine mandate is "morally wrong".

It remains to be seen whether world number one Djokovic will defend his Australian Open title in Melbourne in January due to vaccination requirements.

The state of Victoria, where the year's opening grand slam takes place at Melbourne Park, has introduced a vaccine mandate for professional athletes and across most industries amid the coronavirus pandemic.

The 2021 Australian Open went ahead, albeit in February instead of January, and without fans for most of the tournament following a snap lockdown of Melbourne due to COVID-19.

Djokovic was among the players critical of the conditions athletes endured prior to this year's Australian Open, with strict quarantine measures introduced.

Kyrgios and Djokovic have clashed in the past, but the former backed the nine-time Australian Open champion as he called for the upcoming grand slam to be scrapped.

"I don't think the Aus Open should go ahead, just for the people in Melbourne – you’ve got to send a message," Australian former world number 13 Kyrgios said on his 'No Boundaries' podcast.

"How long did [Melbourne] do in lockdown? 275 days or something?"

Kyrgios also referenced Brooklyn Nets star and NBA champion Kyrie Irving, who is yet to feature this season due to his refusal to be vaccinated against coronavirus, which is preventing him from practicing or playing – New York has a mandate in place that states players must have had a COVID-19 jab.

Kyrgios – an Australian Open quarter-finalist in 2015 – added: "Kyrie, Novak … These guys have given so much, sacrificed so much. They are global athletes who millions of people look up to.

"I just think it is so morally wrong to force someone to be vaccinated.

"I'm double vaccinated, but I just don't think it's right to force anyone [to be vaccinated] and say 'you can't come and play here because you're not vaccinated'.

"There are other solutions around it, [such as] to get tested every day. In the [United] States I know they've got rapid tests, and it's coming to Australia. It's 85 per cent success rate, you wait 15 minutes and then you're allowed to play."

Victorian sports minister Martin Pakula hit back on Tuesday, telling reporters: "I really like Nick Kyrgios and I cheer for him every time he plays and I certainly don't want to have beef with Nick Kyrgios but I actually couldn't follow the logic of his comments. We've had a long lockdown so the Australian Open shouldn't proceed? I'm not sure I follow that.

"I think the opposite applies. Melburnians, Victorians and, frankly all Australians, are absolutely gagging for major events. Our economy needs it, our state psyche needs it. It's a global grand slam, it's going to go ahead."

Roger Federer is unlikely to compete at next year's Australian Open, but the 20-time grand slam champion is not yet thinking of retirement, so says coach Ivan Ljubicic.

Federer has endured an injury-hit two seasons. After reaching the semi-finals at the 2020 Australian Open, the Swiss star underwent knee surgery, with a complication in his recovery leading him to take the rest of the year off.

That prolonged rehabilitation, plus the strict COVID-19 regulations in Australia, meant he did not compete in Melbourne earlier this year, but Federer returned to the ATP Tour in Qatar in March.

He went on to reach the last 16 of the French Open, losing to Matteo Berrettini, and the quarter-finals at Wimbledon, where he went out to Hubert Hurkacz.

However, he has not featured since then after undergoing surgery for another knee problem sustained on the grass-court circuit.

With Australia's tight coronavirus restrictions still in place, it is unclear whether Novak Djokovic, who has tied level with Federer and Rafael Nadal on 20 major wins, will compete in Melbourne early in 2022.

Nadal, too, has not yet confirmed his participation, and with Ljubicic suggesting Federer will not be fit in time, all three greats could be missing from next year's first grand slam.

"I think there are very few chances, he is still recovering and knowing him he wants to be sure he can play to win the tournament and be at 100 per cent," Ljubicic said.

"So I think Australian Open is not a real possibility right now. But he will go step by step because he is 40 years old and he needs to be patient. He cannot recover as quickly as he used to."

Despite doubts over his participation in Australia, and the time he has spent away from the court in the past two years, Federer is not considering retirement just yet.

"We have spoken and I can guarantee he wants to return playing tennis," Ljubicic added. "When he will decide to stop, he will retire, but I don't think it's going to happen all of a sudden."

Ljubicic is only two years Federer's senior and, as a player, reached a high of world number three back in 2006. He has coached Federer since 2016, helping him to three grand slam titles.

"Many times I found myself wondering what am I doing here? But in the end I hope and I think I was able to help him in those few moments he needed in the right way at the right time," Ljubicic said.

"There's always a risk when you meet your idol in person, as you may discover something you don't like, but with him, it is not the case. With him, there are no risks, he really is an extraordinary person. 

"I have been lucky enough to live beside him in the past six years and I enjoyed it very much. I really have fun with him. Is it difficult? No, it's just beautiful. When we discuss tennis, I ask myself: why he is paying me?"