Rafael Nadal declared his Abu Dhabi mission a success despite suffering a second consecutive defeat at the Mubadala Tennis Championship on Saturday.

After a hard-fought battle with Andy Murray on Friday served up a reminder of many a classic match between the pair, it was Denis Shapovalov who beat Nadal in his second comeback clash.

Since losing to Novak Djokovic in the French Open semi-finals in June, Nadal had played only two matches due to a worrying foot injury.

That has been a long-term problem and the 35-year-old Spaniard chose this week's event to test how it would stand up to match conditions.

Canadian Shapovalov beat his fellow left-hander 6-7 (4-7) 6-3 10-6, but Nadal has done enough in his two matches, and in a practice session with Andrey Rublev, to be persuaded his prospects for 2022 are looking up, with the Australian Open just a month away.

The 20-time grand slam champion said: "Maybe it was too tough to start after a long time."

But he was laughing as he said that, and added: "The goal is achieved: to be back on court. I've played two matches and played more or less four hours on court.

"I enjoyed it. Congrats to Denis today. I wish you all the very best for the next season, and I'm going to try to keep going with my road."

Nadal said he would return to the tournament in future years, as long as he remains fit and still on tour.

"If I'm still playing tennis, I am always super happy to be here playing," he said. "Hopefully I can keep coming during the next couple of years."

Shapovalov, 22, is one of the ATP Tour's most talented youngsters, striving to make a telling impact while the likes of Nadal, Novak Djokovic and Murray reach the twilight years of their careers.

He said of Saturday's win over Nadal: "Any time I get to go on court against a guy like Rafa is an honour for me.

"It's great to just see you back on the court and see you healthy. Hopefully you can grab a great season and keep going."

Rafael Nadal said it felt "special" to be back on court as the 20-time grand slam champion began his latest comeback with defeat to old foe Andy Murray in Abu Dhabi.

The Spaniard was beaten 6-3 7-5 by Murray at the Mubadala World Tennis Championship, an exhibition event that for the 35-year-old marks an important step towards a full ATP tour return.

Nadal is coming off a year disrupted by the foot injury that caused him to miss Wimbledon, the Olympics and the US Open, playing just one event after June.

With the Australian Open a month away, there is plenty of work for these two still to do, but this was a feast for the eyes as the multiple grand slam champions jostled hard for supremacy.

Murray is down at 134th in the ATP rankings and continues to battle his own body after hip and groin problems. However, eye-catching wins late in the season against the likes of Carlos Alcaraz, Hubert Hurkacz, Jannik Sinner and Frances Tiafoe have suggested there might be good times ahead for him in the new year.

Here the Scot broke Nadal's serve to 15 in the sixth game of the first set to seize the initiative. Nadal appeared to be finding a familiar rhythm in the second set, hitting some tremendous clean winners, and at 0-30 down at 4-4 he serve-volleyed twice in succession to get out of trouble.

A contentious line call gave Murray two break points at 5-5, and although Nadal saved one, he fired long at the end of a super rally on the next point. Murray closed out the contest on his second match point, with Nadal flinging a full-throttle backhand long, 

"It's been special to be back in competition," Nadal said in an on-court interview. "At the same time, it's been a while since we played against each other. I'm super happy to see Andy playing at this great level after all the things he went through.

"For me, as a comeback it was not a bad match for me. It's been a long time since I was out on court in a professional match so I've got positive feelings."

These wily old rivals had met 24 times previously at competitive tour level, all of those encounters coming between 2007 and 2016 with Nadal leading 17-7 in the head-to-head.

Nadal won the ATP's comeback player of the year award way back in 2013, and he finds himself looking to prove himself again in 2022, locked together on 20 slams with Novak Djokovic and Roger Federer.

Murray, who has won three slams but also been a runner-up eight times in the majors, said: "It's great to be back on the court, able to play at a high level again after a very long time. Me and Rafa have played so many tough matches, but we've not played for five or six years.

"That shows both of us have gone through lots of injury troubles and issues, and it's great to just have the opportunity to be on the court with him again.

"Certainly when I was younger I wasn't appreciating it as much as I do now. It's great to be back on the court, I'm so happy that Rafa's back, and I look forward to the next few years."

Murray will play Andrey Rublev for the title on Saturday, while Nadal features again too, taking on Denis Shapovalov in a third-place match.

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.

US Open champion Emma Raducanu will miss this week's Mubadala World Tennis Championship after testing positive for coronavirus.

The 19-year-old had been due to take on Tokyo Olympics gold medallist Belinda Bencic in the exhibition event in Abu Dhabi.

However, Raducanu announced on Monday that she will not be able to take part in the tournament as she is now self-isolating. 

"I was very much looking forward to playing in front of the fans here in Abu Dhabi, but unfortunately after testing positive for Covid-19, I will have to postpone until the next opportunity," Raducanu said.

"I'm isolating as per rules and hopefully will be able to get back on court soon."

Raducanu became the first qualifier to win a grand slam title with victory at Flushing Meadows in September, but she has won just two of her five matches since then.

The British teenager, who recently appointed Torben Beltz as her new coach after parting company with Andrew Richardson, will next be in action at the Melbourne Summer Set early in the new year as preparation for the Australian Open.

Spanish tennis great Manolo Santana, a four-time grand slam winner, has died at the age of 83.

Santana won the US Open, Wimbledon and the French Open twice during the 1960s, during which time he spent a period as world number one.

He also won the men's singles tennis tournament at the 1968 Olympics, though it was not recognised as a medal event at the time, while also winning the French Open men's doubles in 1963 and the Davis Cup with Spain on three occasions.

Santana retired in 1977 and in more recent times was regularly seen watching countryman Nadal – the only Spaniard to have won more grand slam titles – from the stands.

Nadal led the tributes to Santana on Saturday with an emotional post on social media.

"I have just received the terrible news of the death of our great Manolo Santana," he wrote on his official Instagram account.

"As I have said many times in the past: thank you very much for what you did for our country and for leading the way for so many. 

"You have always been a reference, a friend and a person close to everyone.

"We will miss you Manolo; you will always be unique and special. Greetings to your family and a lot of strength at this time. We will never forget you."

Andy Murray has parted ways with his long-term coach Jamie Delgado ahead of the 2022 season.

Murray and Delgado joined forces during the 2016 season when the Scot won a second Wimbledon title and finished the year top of the world rankings.

Former professional player Delgado, 44, then stepped up as full-time coach when Ivan Lendl stopped working in the role the following year, though much of his time has been spent with Murray negotiating a hip injury.

Delgado will now move on to go work with Denis Shapovalov's team, while Murray will continue to trial with Jan de Witt at an exhibition event in Abu Dhabi.

The 34-year-old had previously been working Johanna Konta's former coach Esteban Carril at a Stockholm tournament in November, but the Spaniard will not be part of Murray's setup for the upcoming season.

Potential new coach De Witt counts Gilles Simon, Gaels Monfils and Viktor Troicki as former players he has worked with, and the German will be with Murray for his first match against Dominic Thiem at the Mubadala World Tennis Championship.

Murray, who has dropped to 134th in the world rankings, will face Rafael Nadal if he can beat the Frenchman, while Emma Raducanu will also be in action in Abu Dhabi.

World number one Ash Barty will start her 2022 season at the Adelaide International along with eight of the other current 10 top players in the world.

Barty has held top spot in the women's rankings since September 2019 and collected five titles – including Wimbledon – in the 2021 season but missed the French Open with a hip injury.

She also opted to not play in the season-ending WTA Finals in Mexico due to coronavirus-enforced quarantine concerns that could disrupt her preparation for the following campaign.

The Women's Tennis Association (WTA) confirmed on Friday that Barty would begin her 2022 season in Adelaide on January 2, along with defending champion Iga Swiatek, WTA Finals victor Garbine Muguruza and Roland Garros winner Barbora Krejcikova, as the world's elite players prepare for the Australian Open.

The entry list for the WTA 500 tournaments also includes Tokyo Olympics gold medallist Barbara Bencic, who finished runner-up to Swiatek in 2021, former world number one Karolina Pliskova and US Open runner-up Leylah Fernandez.

The field boasts 12 major trophies between them, but three grand slam winners will kick-start their seasons in Melbourne the day after.

Naomi Osaka, who is aiming to defend her title at the Australian Open, gets her preparations underway in the Melbourne Summer Set.

Two-time major winner Simona Halep and reigning US Open champion Emma Raducanu will play in the Melbourne Summer Set.

The trio are among 20 of the top 50 ranked players in the world for the two WTA 250 tournaments starting on January 3, with the entry list split between the competitions the week before matches start.

Raducanu will feature in just her eighth Tour-level event, and her fourth tournament since winning her first major, while Osaka will be appearing for the first time since an early defeat in the third round of the US Open to Fernandez.

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.

Amelie Mauresmo has become the first woman to be appointed tournament director at the French Open, promising to show "fierce ambition" in the role.

Former Wimbledon and Australian Open champion Mauresmo succeeds fellow former tour professional Guy Forget in the top job at Roland Garros.

Mauresmo enjoyed 39 weeks at number one in the world at the height of her career but struggled to stamp a mark at her home grand slam. She captured the junior title in 1996 but appearances in the 2003 and 2004 quarter-finals were her best performances as a professional.

The 42-year-old aspires to make a greater impact on the Paris tournament during her time in charge, having been appointed to serve until 2024.

She steps into the role after spending several years working successfully as a coach, having helped players including Marion Bartoli, Andy Murray and Lucas Pouille. She and Pouille parted company in October of last year.

Mauresmo said she was "very proud" and explained: "This tournament created a vocation within me. I started dreaming about tennis thanks to Roland Garros! At age four, I sat in front of the television and decided I wanted to become a tennis player, thanks to 'Roland'.

"I stayed here in the National Training Centre when I was younger, I played in the grounds. It was my playground! This site is still very dear to me, even though the stadium has changed a lot. I qualified at age 15, I won the junior tournament.

"My career here featured many ups and downs, in part due to all those emotions I experienced when I was younger. And, after my career, I saw a different side to the event. I have coached various players, been a television pundit, a spectator and a television viewer, too. I don't know if anyone has seen the tournament from more angles than I have.

"This gives me a certain responsibility and a fierce ambition to push Roland Garros even further. The event is already fantastic, extraordinary. We are going to try and make it even better!"

Mauresmo, who retired from playing in 2009, has also served as France's Fed Cup captain.

Tennis great Billie Jean King sent a message of congratulations, and French sports minister Roxana Maracineanu welcomed the appointment.

Maracineanu said: "I salute the arrival of Amelie Mauresmo at the head of the most beautiful tennis tournament in the world. As well as being an exceptional athlete and an engaging women, she represents the necessity of tolerance and modernity. Bravo."

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.

Ash Barty has won the WTA's Player of the Year award for a second time, while Emma Raducanu's sensational 2021 season was capped with the Newcomer of the Year prize on Tuesday.

Barty collected the tour's top individual year-end award in 2019, having won the French Open and finished that season as the world number one.

And after Sofia Kenin succeeded her in 2020, Barty is back on top this year.

This was the third straight season the Australian superstar claimed the year-end number one ranking, and it saw her land a second major title at Wimbledon. Barty's five WTA titles in 2021 were unsurpassed.

But she has had to share the limelight in recent months with Raducanu, and that was the case again as the 19-year-old Briton was unsurprisingly hailed as the tour's star newcomer.

Raducanu became the first qualifier to win a grand slam when she swept to glory at the US Open, having also impressed in a run to the last 16 at Wimbledon.

The teenager, who has risen from 343rd to 19th in the rankings in the past year, won 10 straight matches without dropping a set from the first qualifying round to the final at Flushing Meadows.

Elsewhere, Roland Garros champion Barbora Krejcikova collected a pair of awards, scooping Most Improved Player and, alongside Olympic, WTA Finals and French Open-winning partner Katerina Siniakova, the Doubles Team of the Year.

Carla Suarez Navarro, who retired in 2020 and was then diagnosed with Hodgkin's Lymphoma, returned to the tour cancer free in 2021 for a farewell season and carried off the Comeback Player of the Year award.

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."