Juan Martin del Potro will undergo knee surgery for the fourth time but retains hope of playing at the Olympic Games in Tokyo.

Del Potro, who was a career-high world number three in August 2018 and still in the top 10 fewer than two years ago, has not appeared on the ATP Tour since withdrawing from the Queen's Club Championships in 2019.

The 2009 US Open champion had his first procedure after falling at the tournament in London and another followed in January 2020.

The third operation came last August as pain persisted, but the issue still has not been eradicated.

However, Del Potro said in an Instagram post on Monday that the death of his father earlier this year had motivated him to continue pursuing a return to the court.

The 32-year-old, who won bronze for Argentina at the 2012 Olympics and silver four years later, will go under the knife again in Chicago on Tuesday.

"We've tried conservative therapy but the pain is still there," he wrote.

"[Doctor Jorge Chahla] knows I want to play tennis again and be able to play the Olympics, so we agreed that surgery should be done as soon as possible.

"Of course, these last few weeks weren't easy for me. Everything's so hard since my father's passing.

"But also, I feel the strength he sends me from above. I had this day in which I woke up and called the doctor. I knew I had to try again.

"I hope I can overcome this painful situation. I won't stop trying. Of course, your messages and best wishes are always welcomed. Thanks for the love."

Tokyo 2020 organisers have announced spectators will not be allowed to travel from overseas to watch the Olympic Games this year.

The measure has been taken as part of an effort to reduce the risks of COVID-19 spreading at the delayed Games.

The Games will run from July 23 to August 8, having been set back by a year due to the global health crisis.

Also affected will be the Paralympics, which runs from August 24 to September 5, with travelling spectators also barred from attending.

The International Olympic Committee (IOC) and International Paralympic Committee (IPC) have been advised of Tokyo's decision and are said by Games chiefs to "respect and accept this conclusion".

In a statement issued on Twitter, Tokyo 2020 said: "Today, on March 20, we reported to the IOC and IPC that we would not accept overseas spectators to Japan in order to realise a safe and secure event.

"We will continue to do our utmost to make this summer's event a safe and secure event so that it will be a light of hope for people all over the world."

In a further statement, Tokyo 2020 organisers said tickets purchased by those planning to travel from abroad would be refunded.

They said the coronavirus situation within and beyond Japan "remains very challenging" and pointed to travel across borders being "severely restricted", meaning entry to Japan could not be guaranteed.

"In order to give clarity to ticket holders living overseas and to enable them to adjust their travel plans at this stage, the parties on the Japanese side have come to the conclusion that they will not be able to enter into Japan at the time of the Olympic and Paralympic Games," said the Tokyo 2020 statement.

"This conclusion will further contribute to ensure safe and secure Games for all participants and the Japanese public."

Texas A&M’s Tyra Gittens wants to wrap up qualification for the Olympic heptathlon as soon as the outdoor season begins, but if she doesn’t, she is confident that there are other ways for her to get to Tokyo.

Los Angeles Clippers star Kawhi Leonard is planning to represent the United States at the rescheduled Olympic Games in Tokyo this year.

Coronavirus forced the 2020 Games to be postponed, with the Olympics now due to be held in Tokyo from July 23 to August 8 this year.

Despite a potentially congested schedule, with the Clippers contenders in the Western Conference and the NBA season set to finish on July 22 if the Finals go the distance, Leonard is ready to play for Team USA.

"My plan is to go," Leonard said on Sunday, ahead of the All-Star Game in Atlanta.

Gregg Popovich's Team USA are set to play their first game against France on July 25.

"If I feel up to it and feel ready to go around that time, then I'm going to play," Leonard said.

Leonard added: "A lot of people were in for 2020, but just the pandemic pretty much killed everything."

Team USA won the Gold Medal in 2016, defeating Serbia at the Rio De Janeiro Games almost five years ago in Brazil.

Jamaica’s Olympic-bound gymnast Danusia Francis believes her inclusion in Simone Biles’ Gold Over America Tour is another opportunity for her to highlight Jamaica’s gymnastics on an international stage.

Usain Bolt's one-time great rival Yohan Blake has declared he will refuse all COVID-19 vaccines, and would rather miss the Tokyo 2020 Olympics than be immunised.

The Jamaican sprinter won silver in the 100 metres and 200m at London 2012, as Bolt landed gold in both races. Only Bolt has ever run faster than Blake over those distances.

Speaking on Saturday, Blake expressed his opposition to being given a vaccine.

The International Olympic Committee has indicated athletes will not need to be vaccinated before taking part in the Tokyo Games, but vice-president John Coates recently said it was "certainly being encouraged".

The Olympics, postponed from last year due to the coronavirus crisis, is due to run from July 23 to August 8.

Quoted by the Jamaica Gleaner newspaper, Blake said: "My mind still stays strong, I don't want any vaccine, I'd rather miss the Olympics than take the vaccine, I am not taking it.

"I don't really want to get into it now, but I have my reasons."

Blake, who won 100m gold at the 2011 World Championships, is now 31 and Tokyo may be his last chance to shine on the Olympic stage.

He said in a video posted late on Saturday night: "Love me or dislike me, but I am here for a reason, to serve God, and at the same time be a servant for God to help each and every one.

"I am a righteous man, I am a man of God, and I believe that everybody do have a choice in life, no matter what. And I want to tell someone, don't let anyone take away that choice from you.

"At the end of the day if anything should happen, nobody's going to be by your side apart from God. No one is going to be there to hold your hand, it's going to be you.

"Follow your mind, don't follow the crowd. At the same time, be respectful to each and every one. Don't let no one take away your choice."

Jamaica has had 422 confirmed deaths from COVID-19, and 23,263 cases, the country's government announced on Saturday.

The country has yet to receive first shipments of a vaccine, but health minister Dr Christopher Tufton said on Friday they would "soon" arrive.

The Jamaica Olympic Association and the Olympians Association of Jamaica have paid tribute to Olympian Les Laing, who died on the weekend.

Laing, who was born in Linstead, St Catherine on February 19, 1925, represented Jamaica at the 1948 and 1952 Olympics was a member of the famed 4x400m relay team that won gold in Helsinki. He is the third member of the iconic quartet to have died leaving behind George Rhoden as the only surviving member.

Arthur Wint died in 1992 while Herb McKenley passed in 2007.

“The Jamaica Olympic Association (JOA) mourns the loss of a member of our household but celebrates the life he lived inspiringly on the track which mirrored the personality of this son of Linstead,” the JOA said in a statement released on Sunday.

“Leslie Alphonso Laing's feats as an Olympian are well documented and we salute him with grateful hands. But more importantly, it is the spirit of the gentlemen which has inspirited generations of athletes and earned the abiding respect of a nation.

“In a world where recorded statistics of sporting achievements are understandably cited in praise of men, the JOA reflects deeply and respectfully on Laing's self-sacrificial service to his country and the soul of his ground-breaking feet.”

Meanwhile, the OAJ described Laing as a hero.

OAJ President Marvin Anderson said he one of the nation's Olympic pioneers.

“Arthur Wint, Laing, Herb McKenley and George Rhoden set a world record 3 minutes 03.9 seconds to defeat a top-class US team at the Games in London,” Anderson said. "His heroic relay run of 47 seconds flat was all the more remarkable because he was a specialist 200-metres man."

Laing, Anderson said, leaves behind a substantial legacy from his days on the track.

“While many Jamaican track stars emerged from the US college circuit, the Linstead-native rose to prominence in Britain as a member of the Polytechnic Harriers Club in London. Fittingly, he made his Olympic debut in that city in 1948, placing sixth in the 200 metres final with McKenley fourth.

 “An injury to Wint in the 4x400 final prompted Laing and his teammates to vow to return and win four years later in Helsinki, Finland. Running faster in every round, Laing became the first Jamaican to reach an Olympic sprint final twice and improved his finish to fifth place. Despite his short stature, he delivered a stout-hearted second leg run to help Jamaica to fulfil the promise made in London.”

 Laing retired after a 1954 season when he narrowly missed taking the sprint double at the CAC Games in Mexico City where he won the 200 and took silver in the 100m.

Laing was recognized by the respected US publication TRACK AND FIELD NEWS, which listed him in its annual world rankings three times - at number 9 in 1948, number 10 in 1949 and at number 9 once more in 1953.

"His accomplishments paved the way for Jamaica in the sprints," Anderson said.

 “In fact, no other Jamaican would reach back-to-back Olympic 200m finals until Don Quarrie did it in 1976 and 1980. Mr Laing was a pioneer who showed us what was possible for us in the 200 and thanks to the start he provided, Jamaica has excelled in that event."

Laing was married to 1948 high jump finalist Carmen Phipps.

Leslie Alphonso "Les" Laing, a member of Jamaica’s gold medal-winning mile relay team at the 1952 Olympics in Helsinki has died.

Olympic and World 400m champion Kirani James has revealed that while his Grave’s Disease is under control he is not yet certain when he will open his season despite the fact the Olympics are only six months away.

Anderson Peters, the 2019 World Championships javelin gold medalists believes it is well worth the risk travelling to Japan to compete at the Olympic Games this summer, despite the threat posed to his safety by the Covid-19 virus.

Anderson Peters, the 2019 World javelin champion, is thankful that the Olympics were postponed from 2020 because of the pandemic as it means he now has a legitimate shot at winning a medal, perhaps gold, when the Games convene in Tokyo, Japan this coming summer.

Rafael Nadal wants to play at the Olympics but the star said fitting more quarantining into the ATP Tour calendar looked "difficult".

After being postponed last year due to the coronavirus pandemic, the Games are scheduled to start in Tokyo on July 23.

Naomi Osaka said she would be willing to quarantine ahead of the Olympics, with players having gone through similar in preparation for the Australian Open.

Nadal, an Olympic gold medallist in singles and doubles in 2008 and 2016 respectively, said he would listen to the experts, but acknowledged quarantining could be tough.

"It's the same as always. I am nobody to have a clear opinion on that.  I am just a tennis player, a human person that doesn't have enough knowledge about all the situation," the Spanish star told a news conference on Sunday.

"What we have to do is just follow the instructions of what the people who really have the right knowledge of all this stuff give to us. What's going to happen in Tokyo for the Olympics, if the Olympics are going to happen or not, or if we have to do quarantine before Olympics for 15 days or not, seems like a sports perspective very difficult because it's difficult for us, I don't know, combining our Tour with another 15 days of quarantine to play Olympics. It looks difficult to fix it in our calendar.

"But, as I said, we're going to do what the people who know about virus and who know about protecting the people in every single country, [we] are going to just follow their instructions."

Asked if his intention was to go, Nadal said: "I think everybody wants to play in Olympic Games, then let's see what's going on."

Nadal and Spain will begin their ATP Cup campaign against Australia on Tuesday.

Naomi Osaka would be prepared to spend another two weeks in quarantine to be able to play at a "very special" Olympics in Tokyo.

Postponed due to the coronavirus pandemic, the Games are scheduled to begin on July 23 this year.

This year's Australian Open will begin on February 8 after players quarantined ahead of the first grand slam of the year.

Osaka said she would be prepared to do it all again if it meant she got the chance to play at the Olympics.

"Honestly, my concern isn't the athletes. The way that I feel is I will stay in my room for two weeks to play the Olympics. I missed out on the last one," the Japanese star told a news conference on Sunday.

"Playing in Tokyo would be very special to me. My concern would be the general safety of everyone else because you're opening the country.  Everyone is flying in from different places. I would just want the public to feel safe.

"I feel like the athletes definitely would want to play, but I would want the public to feel safe."

Doubts have also been cast over the Olympics going ahead this year due to COVID-19.

Osaka, a three-time major champion, said while people she had spoken to were excited, some were worried.

"For me the people that I've spoken to, they're really excited about it, but they're concerned because, I don't know, there's just like so many different people entering. I don't know," she said.

"For the people I've talked to, they said as long as everyone is safe, as long as Japan is getting better and not worse, then it should be okay.

"But for me, hmm, don't quote me on that."

Ahead of the Australian Open, Osaka is playing the Gippsland Trophy, where she will face either Alize Cornet or Ajla Tomljanovic in the second round.

Olympic chiefs have been joined by the Japanese government in denying a report that the Tokyo Games is poised to be called off for a second time.

The delayed Tokyo 2020 event is due to officially open on July 23 and close on August 8, having been put back by a year because of the COVID-19 health crisis.

However, with the pandemic still causing devastation in countries across the globe, there have been concerns that staging an Olympics in 2021 may be impractical.

British newspaper The Times quoted an unnamed senior Japanese government source as saying: "No one wants to be the first to say so but the consensus is that it’s too difficult. Personally, I don't think it's going to happen."

That is a perspective that is hotly disputed, with International Olympic Committee (IOC) president Thomas Bach telling Kyodo News: "We have at this moment, no reason whatsoever to believe that the Olympic Games in Tokyo will not open on the 23rd of July in the Olympic stadium in Tokyo.

"This is why there is no plan B and this is why we are fully committed to make these Games safe and successful."

Japan has strict border controls in place in an attempt to prevent travellers spreading coronavirus and bringing new strands of the virus into the country.

The IOC executive board is due to meet on January 27, when it is set to receive updates from the Tokyo organising committee.

A recent poll of Japanese public, conducted by broadcaster NHK, found there was widespread opposition to the Olympics going ahead this year.

The Times said Tokyo would look to host the 2032 Olympic Games.

Yet Australian John Coates, an IOC vice-president and chair of the Tokyo Coordination Commission, says the plan remains for the Games to be held in its current slot.

"There has been no discussion on cancellation," Mr Coates told The Ticket, an ABC radio show.

"At the end of the day, politicians do have to take into account the feelings of those inside their party and the general public.

"But this is not the message we are getting from Prime Minister Yoshihide Suga or the president of the Tokyo Organising Committee Yoshiro Mori, himself a former Prime Minister."

In Japan, deputy chief cabinet secretary Manabu Sakai told media that the prospect of a Games cancellation was not under consideration.

He said: "There is no such fact. I would like to deny it. The government is working as one to prepare for the success of the event this summer."

The Australian Olympic Committee (AOC) said it is continuing to plan for the Olympic Games, despite reports the rescheduled showpiece event in Tokyo could be cancelled amid the coronavirus pandemic.

COVID-19 forced the 2020 Games to be postponed, with the Olympics now due to held in Tokyo from July 23 to August 8 this year.

But with coronavirus continuing to wreak havoc globally, there are reports claiming Japan has privately concluded the Olympic Games will have to be called off.

The AOC responded to the reports in a statement on Friday, which read: "Both Japanese prime minister Suga and IOC president Bach have this week strongly reaffirmed their commitment to the Tokyo Olympic Games going ahead in July this year. 

"The AOC is continuing its planning to ensuring the Australian Olympic Team arrives in Tokyo, competes and returns home safe and COVID-free.

"The AOC, Federal Government, Queensland Government and Brisbane City Council are continuing to progress the candidature for the Olympic Games to be held in Queensland in 2032 – and that process continues."

International Olympic Committee (IOC) president Thomas Bach also insisted the Games will take place this year, despite surging COVID-19 cases in Tokyo.

Amid growing doubts, Bach told Kyodo News on Thursday: "We have at this moment, no reason whatsoever to believe that the Olympic Games in Tokyo will not open on the 23rd of July in the Olympic stadium in Tokyo.

"This is why there is no plan B and this is why we are fully committed to make these Games safe and successful."

"You may not like it but sacrifices will be needed. This is why I'm saying, safety first, and no taboo in the discussion to ensure safety," added Bach after hinting at the possibility of reduced spectators.

Bach said: First of all, let me be clear that you cannot compare March 2021 with March 2020 because there is such great progress in science, medicine, vaccination and [virus] tests.

"All this was not available in March last year. Nobody knew yet how really to deal with the pandemic, and now we know much more."