Andy Murray

In a stacked women's draw, world number one and Wimbledon champion Barty has a tough opening assignment and could face French Open finalist Anastasia Pavlyuchenkova, the 13th seed, as early as round three.

Spectators may not be in attendance at Tokyo venues for the Olympics but Japanese fans will be rooting for Osaka, who returns to action after a two-month hiatus with the four-time grand slam winner having spoken openly about mental health and anxiety issues.

Viktorija Golubic or Maria Camila Osorio Serrano would await Osaka if she can get through round one, but a dream final with Barty is no shoo-in given 15 of the world's top 20 on the WTA Tour are in action including each of the nine leading the race for the 2021 WTA Finals.

Aryna Sabalenka (3), Elina Svitolina (4), Wimbledon runner-up Karolina Pliskova (5), Iga Swiatek (6) and Garbine Muguruza are all featuring in Tokyo.

The men's side has been hit by a spate of withdrawals, with Rafael Nadal, Roger Federer and Dominic Thiem among those not playing in the Japanese capital.

The main talking point surrounds whether the all-conquering Djokovic can continue his march towards a calendar Golden Slam – a sweep of all four majors and an Olympic gold in the same year.

Any notion of a free ride for the Serbian is wide of the mark, though. His side of the draw could see him come up against Andrey Rublev (5), Alexander Zverev (4) and Hubert Hurkacz (7), while Stefano Tsitsipas (3) – beaten by Djokovic in the French Open final – and Daniil Medvedev (2) are among the potential final opponents.

Andy Murray, gold medal winner in 2012 and 2016, faces Canada's Felix Auger-Aliassime in a tricky first-round match.

At this year's delayed Tokyo Games, there is the prospect of seeing several of the world's top athletes all competing for gold at the same time.

August 1 looks a good bet for the standout day in 2021.

The final round of the men's golf event could see Rory McIlroy and Jon Rahm in the mix, with Andy Murray hopeful he will meanwhile be defending consecutive singles gold medals in the tennis.

This comes on the same day that Simone Biles could potentially become the most decorated Olympic gymnast of all time.

As if that were not enough, the men's 100m final is another must-watch event.

Expectations will be high heading into that second Sunday of the Games, with examples from the past three competitions living up to their billing...

AUGUST 16, BEIJING 2008

Michael Phelps and Usain Bolt would be firmly in contention to appear on the Games' own Mount Rushmore and each enjoyed one of the finest moments of their respective careers on the same day.

Phelps had spent the opening week of the Beijing Olympics pursuing Mark Spitz's 1972 record of seven golds and had six as he entered the pool again for the 100m butterfly final, almost 12 hours before Bolt's big moment.

Seventh at the turn, the United States superstar needed a remarkable recovery to triumph over a devastated Milorad Cavic by 0.01 seconds.

Phelps would pass Spitz with his eighth gold of the Games the following day, by which point he was sharing the headlines with Jamaica's own ultimate athlete.

Bolt's blistering 9.69-second final triumph in the 100m stood as a world record until the same man beat it exactly a year later. The new benchmark remains unmatched.

And that Saturday in China also saw the small matter of Roger Federer's only gold medal, claimed alongside Stan Wawrinka in the doubles final after falling to James Blake as the top seed in the singles.

AUGUST 4-5, LONDON 2012

It is actually tough to choose just one day from the 2012 Olympics, where this weekend delivered from start to finish.

On the Saturday evening, at the Aquatics Centre, swimming prepared to say goodbye to its greatest name. Phelps and the United States won the 4x100m medley, clinching his 18th gold medal in what appeared set to be his final race.

Indeed, Phelps confirmed his retirement following the Games, only to return in predictably dominant fashion in 2016.

Across the city that same night, Team GB athletes were capping a stunning run of medals that would see the day dubbed "Super Saturday". There were six home golds in all, including big wins for Jessica Ennis, Greg Rutherford and Mo Farah in quick succession.

The drama only continued the next day, too, as Murray finally sealed a Wimbledon win over Roger Federer in the tennis event, while Bolt lit up London Stadium in the 100m.

AUGUST 14, RIO 2016

Although there will be no Bolt brilliance in Tokyo, Brazil was treated to another show as he became the first three-time winner of the 100m – later doing likewise in the 200m.

The first triumph was almost overshadowed on the track, however, coming shortly after Wayde van Niekerk had broken Michael Johnson's 17-year 400m world record by 0.15 seconds.

Again, the excitement was not reserved for athletics, with Murray in action that evening to claim another gold after coming through a four-hour epic against Juan Martin del Potro.

Murray is the only player – men's or women's – to win consecutive singles golds, while Rafael Nadal's presence added a little more stardust even though he lost the bronze final to Kei Nishikori.

A stunning Sunday also saw Biles add to the reputation she takes with her to Tokyo, a third gold on the vault making her the most decorated American gymnast.

And there was history, too, for Justin Rose, as he edged past Henrik Stenson at the 18th hole of the fourth round to become the first Olympic golf champion in 112 years.

The only men to have won each of the singles majors across their careers, plus Olympic gold, are Andre Agassi and Rafael Nadal, and now Djokovic aims to move to the brink of winning all five in his remarkable 2021 season.

Fresh from dominating at Wimbledon, and with the Australian and French Open titles already in the bag, Djokovic heads into the Tokyo Games as a red-hot favourite, seeking to set himself up to complete a historic campaign at the US Open.

Naomi Osaka will enter the Games with almost as much expectation behind her too, the reigning US Open and Australian Open champion eyeing glory for hosts Japan.

But tennis has thrown up a host of shock results in its short Olympic history. Here, Stats Perform looks at the sport's place in the Games.

WHO'S IN, WHO'S OUT, AND WHAT DOES ALL THIS MEAN?

Serena Williams, Roger Federer and Rafael Nadal have all opted out of the Olympics.

Williams made her mind up prior to suffering a leg injury at Wimbledon, although she is already a member of the career Golden Slam club.

Federer reached his decision after revealing he also suffered a physical setback at the All England Club, and Nadal elected to take a two-month break after relinquishing his French Open title.

Don't expect to see them again at the Olympics, given Williams and Federer will be pushing 43 by Paris 2024, and Nadal will be 38. Federer won a doubles gold with Stan Wawrinka in 2008, but his singles peak was the silver medal he earned in 2012, Andy Murray crushing Swiss hopes in the final at Wimbledon.

Dominic Thiem, Bianca Andreescu, Nick Kyrgios, Simona Halep, Angelique Kerber, Victoria Azarenka and Denis Shapovalov are among other confirmed absentees, with fitness issues a factor for some, less so for others.

The COVID-19 crisis is a mitigating factor in why so many stars are staying away, and directly responsible in the case of some players, such as Britain's Johanna Konta and Dan Evans, who both tested positive recently.

But tennis was only fully restored to the Olympic programme in 1988, after being dropped post 1924, and if players are seen to be favouring the grand slams over the Games, that is not such a great look for the sport.

At a time when the International Olympic Committee has shown it is willing to shake up the sports on its programme, tennis could perhaps do with a headline-making Tokyo 2020.

Murray, the two-time defending men's champion, will target an improbable hat-trick. A hat-trick for the injury-hit former world number one would be a sensation, and Osaka landing gold in the women's tournament would surely be one of the great moments of the Games.

DJOKOVIC FOLLOWING IN THE FOOTSTEPS OF GRAF

When Steffi Graf beat Gabriela Sabatini in the women's singles final at Seoul, it completed what we know now as the calendar 'Golden Slam'. She had already won the Australian Open, French Open, Wimbledon and the US Open, and the feat of the then 19-year-old West German has yet to be repeated.

Now Djokovic is three-fifths of the way to a similar clean sweep of the majors and the Olympics, with the US Open getting under way on August 30 in New York.

He teetered on not going to Tokyo, and perhaps he is to some extent endangering his chances at Flushing Meadows by spending more time travelling and enduring bubble life, while others rest up.

But Djokovic is a fiercely proud Serbian and could not resist a great chance of winning gold for his country. He landed bronze at the 2008 Games in Beijing but in 2012 he lost to Juan Martin del Potro in the bronze-medal match, and a cruel draw at Rio four years later saw him assigned Del Potro in the first round.

Top seed Djokovic bowed out in two tie-breaks to the powerful Argentinian, describing the outcome as "one of the toughest losses in my career".

There is no danger of a hat-trick of defeats to Del Potro, which may help Djokovic. Del Potro has been battling for two years to get back to fitness, undergoing four rounds of right knee surgery in a bid to get back on tour.

RAISING THE BAR AT THE OLYMPICS

How the Olympic village functions in Tokyo will be distinctly different to at previous Games, given the pandemic restrictions in place that could be a real buzzkill.

But in the past there have been countless cases of athletes becoming inspired by their surroundings and going on to perform above their usual level.

It can be a party village, and it can also be an eyebrow-raising experience as global superstars rub shoulders with competitors who might struggle for recognition in their home towns. More than anything, the shared team experience, fighting for a collective cause, can make a middling athlete believe they can be great.

Monica Puig was a massive tennis outsider in 2016 but the then world number 34 won the women's singles, stunning Angelique Kerber in the final after beating Petra Kvitova and Garbine Muguruza en route. That gave Puerto Rico their first ever Olympic gold medal.

In 1992, a tournament that featured the likes of Pete Sampras, Jim Courier, Stefan Edberg and Boris Becker finished with a staggering final match-up of Marc Rosset versus Jordi Arrese, who in his home city of Barcelona was edged out 8-6 in the fifth set by the Swiss world number 43. Nobody would have predicted that head to head for gold.

Similarly, at Athens 2004, Nicolas Massu beat Mardy Fish in the gold medal match of a tournament that featured Federer, Andy Roddick, Carlos Moya and Tim Henman.

In the 1996 Atlanta Games, Lindsay Davenport, who had just turned 20, took inspiration from being the daughter of an Olympian, with dad Wink having played volleyball for the United States at Mexico City in 1968.

Davenport was beginning to make an impact on the WTA Tour but was only the ninth seed at the Olympics, yet she swept through the rounds before sinking Arantxa Sanchez Vicario 7-6 (10-8) 6-2 in the final.

"It's like one of those things I look back on and I'm like, 'Was that me?'," Davenport told The Tennis Podcast last year.

"It doesn't seem like it was real. I'd made the transition to the pro tour pretty well, but I liked hanging out between eight and 16 in the rankings. I was very insecure, unsure of what could I do. I liked doing well but I wasn't sure I wanted to do too well because it seemed really overwhelming to be one of those top players.

"Here I go at 20 years old to Atlanta for two or three weeks, in a setting that seemed so comfortable. Look at all these athletes, you have all different shapes and sizes, you have players that are really working hard but have so much in common and you get to hang out with them, breakfast, lunch, dinner in the village."

Davenport was a future world number one and three-time grand slam singles champion, but at this point in her career being an American at an Olympics in the United States was just a thrill.

"You're sharing this with your team-mates who are some of my best friends in Mary Joe Fernandez, Monica Seles. It was the best time ever," she said.

"By the time the tournament actually started we were like, 'Yeah, I'll go play my match and then we'll go back to the village and we'll hang out', and everything went so fast in those few weeks.

"And there I was left standing, winning at the end because I was so incredibly happy and excited with everything that was going on. I kind of forgot what was my job.

"When it became a reality of even just making the team in '96, it was so huge also for my family with having a second generation Olympian."

A 6-2 3-6 6-2 win over Fabio Fognini on Wednesday was enough to see Medvedev through to the last eight at Ariake Tennis Park.

But the world number two struggled with 72 per cent humidity that meant an already hot 31 degrees Celsius felt like 37 degrees Celsius on the heat index.

An extreme heat rule meant Medvedev and Fognini were allowed to leave the court for 10 minutes at one stage of the contest.

Medvedev was in visible discomfort before serving, between points and at changeovers. 

He had two medical timeouts before being asked by the chair umpire Carlos Ramos whether he could continue.

"I can finish the match but I can die," the Russian replied to Ramos, per ESPN. "If I die, are you going to be responsible?"

After the match, Medvedev – who along with Novak Djokovic has been vocally calling for matches to start later in the day to counteract the heat – described his struggles.

He said: "Even from the first set, I didn't feel good enough with my breathing. That's why I called the physio. I felt like my diaphragm had blocked. 

"I couldn't breathe properly. I think it was the most humid day we have had so far.

"Then, on the second set, I just had darkness in my eyes, like between every point I didn't know what to do to feel better. 

"I was bending over, and I couldn't get my breathing together. I was ready to just fall down on the court.  

"I knew there was a 10-minute break. So I went under the cold, freezing shower.

"When you have such a change of temperature and go out on the hot court, you can fully cramp, and it finishes the match for you, either that or you feel better. I was lucky I felt better.

"I don't care too much [about closing the roof], to be honest because I don't know if they have AC [air-conditioning]. 

"It can be actually more humid and hot when they close it, but they should start the matches later. I said it in the first round, and I'll continue saying it.

"All the players I know said this is not normal to start at 11am [local time]. 

"[Djokovic] went to ITF and talked to them, and they gave him reasons - I heard maybe from tomorrow they're going to change it, but let's see."

Following the Medvedev match, organisers were quoted as saying they were "considering" making a change, starting from Thursday's action.

Paula Badosa also struggled on Wednesday and ultimately had to leave the court in a wheelchair after retiring with heatstroke from her quarter-final match against Marketa Vondrousova. 

The Spaniard also withdrew from her mixed doubles match later alongside Pablo Carreno Busta, ending their hopes.

Carreno Busta is still in the singles and will face Medvedev next.

Vondrousova, who had won the first set before her opponent withdrew, said: "It was a big struggle from the beginning because I warmed up in the morning and I felt it was really hot and humid.

"Also, I was a bit tired from Monday because I had doubles too. But I knew [Badosa] had [played singles and doubles] too. 

"I felt like we both were struggling from the beginning. I was just thinking, you have to stay there mentally, just fight for every point and just see what happens."

Set to take part in his fourth Games as he looks to defend the singles title he won at London 2012 and successfully retained at Rio 2016, Murray knows this tournament is likely to be his last at the Olympics.

A creditable and entertaining run to the third round of Wimbledon came amid questions over his long-term future in the game after several years of injury woe.

After losing to Denis Shapovalov at the All England Club, Murray has been drawn to play against another Canadian, Felix Auger-Aliassime, in Tokyo.

He will also play in the men’s doubles alongside Joe Salisbury, with a tough draw in that competition too against Pierre-Hugues Herbert and Nicolas Mahut.

Despite having three grand slam wins, two Olympic titles and a doubles silver medal to his name, Murray believes a podium place in Japan – which he feels is possible – would be a crowning achievement after all he has been through. 

"That is the goal, to try and win another medal," Murray told reporters. "I'm aware that it is not going to be easy. 

"I'm also in a slightly different position to what I was four, five years ago when I would’ve been expected to get one. 

"Maybe that is not the case this time around, but for me, it would probably be my best achievement if I could do that after everything that’s gone on the last few years. 

"I'm motivated for that reason alone and I still believe that I can do that. I still believe that it is possible."

Now 34, it is by no means certain Murray will still be playing and competitive on the ATP Tour by the time the 2024 Olympics take place in Paris.

"I know that this could be the last [Olympics] for me," added the Briton.

"So I want to go out there and leave everything out on the court, fight for every single point because ultimately that’s all you can do."

Having beaten Roger Federer and Juan Martin del Potro in his two Olympic finals, Murray – who revealed he has practiced well and regularly since Wimbledon - hopes his experience of going all the way at the Games will work in his favour.

He added to BBC Sport: "I've prepared as best as I can. I have tough draws in singles and doubles but I think I have a chance.

"If I can get through a round or two I'll start to feel more comfortable. I also have the experience of playing in the Olympics, which I can use to my advantage."

Representing the Russian Olympic Committee, Medvedev appeared fatigued at times in his 6-4 7-6 (10-8) triumph over Kazakhstan's Alexander Bublik at the Ariake Tennis Park.

The conditions in the Japanese capital were sweltering on Saturday but Novak Djokovic was able to keep his cool in coasting to a 6-2 6-2 win against Hugo Dellien.

MEDVEDEV CALLS FOR MORE TIME

Medvedev, who saved three of four break points and now has a 3-0 head-to-head record over Bublik, was pretty pointed about what he feels should be done about the heat.

"Like they do in Mexico, the matches maybe should start at six (pm) because the heat actually gets much, much lighter. We all try to practise at six," said Olympics debutant Medvedev, who next plays Sumit Nagal.

"The fact that we have only one minute between changeovers is a joke. If you ask, let's say 200 tennis players that are here, I think 195 will tell you that one minute is a joke. It should be 1:30.

"But you have to play, that's the Olympics, you go for the medal. You're not here to cry about the heat. It was really tough for both of us. We talked about this after the match on the court. It was unbelievably hot. But you need to get through it."

Fellow Russian athlete Aslan Karatsev (11) defeated Tommy Paul 6-3 6-2 to set up a meeting with Jeremy Chardy, while Lorenzo Sonego (13), Ugo Humbert (14), Fabio Fognini (15) and Alejandro Davidovich Fokina (16) all progressed.

DJOKOVIC UP AND RUNNING

Since winning bronze in Beijing 13 years ago, Djokovic has not had the best of luck at the Olympics – losing in 2012 and 2016 to Juan Martin del Potro on both occasions.

But with a host of big hitters from the ATP absent – including Roger Federer and Rafael Nadal – Djokovic is the overwhelming favourite in Tokyo.

Only Steffi Graf in 1988 from either the WTA or ATP Tour has ever completed a sweep of all four slams and an Olympic gold in a calendar year, and Djokovic needs Olympic gold and victory at the US Open to match the feat.

He needed just 61 minutes here to beat Dellien of Bolivia.

MURRAY SCORES UPSET DOUBLES WIN

Andy Murray is the two-time defending men's singles champion in Tokyo, but struggles with injuries mean it would take a herculean effort to make it three in a row.

But he is also representing Great Britain in the doubles and together with Joe Salisbury upset French second seeds Pierre-Hugues Herbert and Nicolas Mahut 6-3 6-2 in their first time competing with one another.

Murray is not looking too far ahead, though, saying: "You take one match at a time, you know, so a lot of the players here are really motivated to play for their country. 

"This is such a rare opportunity for all of us and I think we all want to do well. So, yeah, just take it one match at a time."

Medvedev beat Italy's Fabio Fognini 6-2 3-6 6-2 on Wednesday in a match that was paused for 10 minutes due to on-court temperatures reaching 31 degrees Celsius, with humidity then adding to that.

The world number two had to receive medical attention on two occasions before he prevailed to tee up a last-eight tie with Pablo Carreno Busta of Spain.

Top seed Novak Djokovic continued his march towards the medal matches with a routine win over Alejandro Davidovich Fokina, though in the doubles, Andy Murray's hopes of winning a historic fourth Olympic prize were shattered.

MEDVDEV'S TEMPER FRAYS IN THE HEAT

It had already been a stressful day for Medvedev. The 25-year-old replied "I can finish the match but I can die. If I die, are you going to be responsible?" when asked by chair umpire Carlos Ramos whether he could carry on playing against Fognini following two medical timeouts. 

Medvedev's temper then boiled over in the media mixed zone when he was questioned over the contentious nature of Russian athletes competing at the Games.

The Russian flag is not represented in Tokyo due to sanctions against the country for state-sponsored doping offences. Russia is suspended from competing in global sporting events for two years – a ban that was reduced from an initial four-year punishment. Instead, athletes are competing under the banner of the Russian Olympic Committee (ROC).

Medvedev was asked if he feels the Russian athletes are "carrying a stigma of cheaters".

Seemingly misunderstanding the question, Medvedev hardly held back in his reaction, saying: "That's the first time in my life I’m not gonna answer a question, man. And you should be embarrassed of yourself."

Before leaving the room, Medvedev subsequently told the press officer: "I think you should [remove] him from either the Olympic Games, either the tennis tournament. I don't wanna see him again in my interviews. Thanks."

MURRAY'S PARIS PARTICIPATION IN DOUBT

There was to be no fairytale title tilt for former world number one Murray. He won gold in the singles in London and Rio, and also managed a silver medal at the 2012 Games in the mixed doubles, but he and Joe Sailsbury suffered a defeat to Croatian pair Marin Cilic and Ivan Dodig in the quarter-finals.

The British pair won the first set but failed to make their advantage count, with Croatia's duo coming back to win 4-6 7-6 (7-2) 10-7.

Murray will be 37 by the time the Paris Games come around, and as he continues to carefully manage his return from hip surgery, the Scot could well have made his Olympic farewell.

"I don't know. I don't know if I'll get the opportunity to play [in the Olympics] again," he conceded.

"I love every minute of playing the Olympics. I wish that today would have gone differently. I had another chance with Joe to win a medal. We were so close and that is just disappointing. There was some stuff I wish I could have done at the end of the match to try and help out more. But yeah, very disappointing."

MIXED BAG FOR TSITSIPAS

While Medvedev, Djokovic and Alexander Zverev all progressed into the last eight in the singles, there was no place for Stefanos Tsitsipas, whose hopes were ended by Ugo Humbert.

The Greek world number four suffered a seemingly innocuous leg injury in the second set tie-break and failed to recover in the decider as Frenchman Humbert claimed the biggest win of his career.

However, Tsitsipas was swiftly back on court to play in the mixed doubles alongside partner Maria Sakkari, and the duo claimed a comfortable 6-3 6-4 victory over Canada's Gabriela Dabrowski and Felix Auger-Aliassime.

Asked after that win to discuss what went wrong in his earlier defeat, Tsitsipas replied: "I figured out a few things later during the match, like really, really late. 

"I think if I've had the same mindset or the same attitude, same vision that I had towards the very end of the match, I think things would have gone much, much smoother and better for me. It's something that I learned."

He also confirmed his injury was "nothing serious."

DJOKOVIC ON A ROLL

As expected, Djokovic is one win away from a shot at a medal in the singles, and he then followed up his victory over Davidovich Fokina by combining with Nina Stojanovic in the mixed doubles.

The Serbian pair beat Marcelo Melo and Luisa Stefani of Brazil 6-3 6-4 in just 70 minutes to book their place in the next round.

Djokovic will have the host nation against him in his next match, however, as he takes on Kei Nishikori, who is Japan's only hope of a singles medal after Naomi Osaka's exit.

A heavy third-round defeat by Denis Shapovalov had left the Scot questioning whether his hard work in training was worth it after years of injury woe as he tried to regain his spot at tennis' top table.

The two-time Wimbledon winner, who has four young children, now feels prepared and revitalised to compete in his fourth Games off the back of his young daughter's accidental wisdom.

Murray told reporters: "When I got home, the day after my match, my daughter said to me: 'Daddy, you're home because you lost another tennis match?'

"I said: 'Yeah, I did. But what do you do when you lose at something?' And she said: 'You try and try again?' I was like: 'Yeah, that's what I want to do.'

"I want to keep playing because I enjoy it and I still think I can play at a good level. 

"There have been difficult moments obviously in the last few months and the last year with the injuries and stuff, but right now this is the healthiest I've been for the longest period in the last year."

Murray will be part of a six-man squad in Japan, including doubles partner and two-time grand slam doubles winner Joe Salisbury, as he looks to defend his Rio 2016 and London 2012 golds.

As the only player to win back-to-back singles titles in Olympic history, Murray still intends to compete at the top-level of tennis for as long as he is able to do so.

"It can be hard and after tough losses like that at Wimbledon - you question a lot of things," the Team GB athlete added to BBC Sport.

"I do still feel like I am capable of playing high-level tennis and when that isn't the case I will stop playing. But right now I don't believe that is the case."

Yet the Games in Japan provides a completely different challenge in 2021 as all athletes remain acutely aware of the coronavirus concerns that surround sport all over the world.

The 34-year-old's Team GB team-mate Johanna Konta is one of many players to miss out due to circumstances linked to the virus.

Murray, who was drawn against ninth seed and Wimbledon quarter-finalist Felix Auger-Aliassime on Thursday, is familiar with the devastating impact a positive result can have after having to miss a major due to COVID-19.

"It happened to me before the Australian Open and I was gutted," he said.

"Thankfully I was able to compete in another grand slam a few months later, but if you've been preparing for something for five years and something like that to happens to you, it would be brutal.

"So there is an anxiousness, but from what I've seen everyone is taking the protocols seriously, so hopefully there won't be too many issues."

Murray will be hoping for few issues on the court too, though he and Salisbury have been drawn in a difficult tie against second-seeded pair Pierre Hugues-Herbert and Nicolas Mahut.

Team GB duo Murray and Joe Salisbury suffered a heart-breaking loss to Croatian pair Marin Cilic and Ivan Dodig at Ariake Tennis Park on Wednesday.

They won the first set but Cilic and Dodig ultimately prevailed 4-6 7-6 (7-2) 10-7, with Murray rueing how close he and Salisbury had come to a semi-final berth that would have guaranteed him a shot at a medal.

Despite falling just short, the two-time Wimbledon winner insisted he did not regret pulling out of the singles tournament to focus on the doubles as he manages a quad injury.

Instead, the singles gold medallist in London and Rio was only looking back to scrutinise some of the decisive points that went against his team.

"No, I don't regret that decision," Murray said. "I think we put ourselves in a really good position to win and do well here. 

"This is the one, it hurts a lot, losing that one, because you get through it, and you get two matches for a medal. 

"We were just so close. I just wish I could have done some stuff differently at the end of the match, so I regret that, not the decision [not] to play singles."

Tokyo could be the last Olympics for Murray, who has had a torrid time with injuries and will be 37 when Paris 2024 comes around.

"Yeah it is just hard – I hate losing," he said when asked about the potential of it being his last Games.

"I don't know if I’ll get the opportunity to play again, I wanted to try and win a medal with Joe. 

"It is difficult to take, it is disappointing – you have regrets and think about points and things you should have done differently. 

"I have always loved team sports. I love being a part of the Olympics as I am sure Joe would say. 

"It is his first time, so I am sure he will be hungry to come back and do more, and do better next time. 

"I know all the tennis players on our team have really enjoyed it and loved the experience, I just wish we could have done better."

Murray added that his leg "felt fine" during the loss, but would monitor how his injury heals before deciding whether he will be able to play the US Open, which starts at the end of August.

The Olympic champion in 2012 and 2016 opted to pull out of the singles prior to his scheduled first-round showdown against Felix Auger-Aliassime on Sunday. 

Instead, Murray decided to continue in the doubles alongside Joe Salisbury, where the pair made the quarter-finals on Tuesday by beating German duo Kevin Krawietz and Tim Puetz 6-2 7-6 (7-2).

It means Murray remains on track for a third straight Olympic gold and he offered a bit of insight behind his decision not to play in the singles.

"I've had a bit of an issue with my quad," he said.

"It's actually not really been causing me many issues on the court like in practice or anything, there was just some stuff showing on the scans that made all the medical team a bit wary about it.

"I said to Joe that if he picked me to play doubles with him then I'd prioritise the doubles over the singles if I had any physical issues and that was the case. 

"It's disappointing for me because I do feel like I've been playing well, and I've loved the Olympics and I would've liked the opportunity to defend my title. 

"But that wasn't to be and now all the focus and energy goes towards the doubles and to try our best to get a medal there."

Marin Cilic and Ivan Dodig await Murray and Salisbury in the last eight.

Alexander Zverev had an altogether more comfortable progression at Ariake Tennis Park, while home favourite Kei Nishikori earned an impressive upset win.

Felix Auger-Aliassime was unable to make the most of two-time defending champion Andy Murray's withdrawal, but it was a good day for Hubert Hurkacz. 

Here's the pick of the action from day two of the men's singles.

TSITSIPAS OUT TO EMULATE GRANDFATHER

Greek ace Tsitsipas, a French Open finalist this year, had to dig deep for a three-set win over Philipp Kohlschreiber.

Should he manage to win gold in the Japanese capital he would be matching the feat of his grandfather, who won the football competition representing the Soviet Union in 1956.

"I've never had the opportunity to meet him. But my mom told me stories of his career and how he got it," he said. "He kind of inspires me in a way. I know what kind of athlete he was, with all the achievements and all the trophies. I'm proud of him. 

"It's something good, a legacy that is being carried on in the family. I'm happy to be the next in the family to be competing at the Olympics."

ZVEREV LOVING OLYMPICS EXPERIENCE

Fourth seed Zverev coasted past Lu Yen-hsun 6-1 6-3 and spoke of how much he is enjoying being around other German athletes.

"Normally you don't have those guys around that much, you have your friends, of course you have people that are around you, but you don't sleep in the same room as them," he said.

"Yes it is very different but in a way very enjoyable. The Olympics are once every four years, and it’s five years now, so I think everybody is enjoying it and everyone is having the best time that they can."

Nishikori is playing at a fourth Olympics and upset fifth seed Andrey Rublev 6-3 6-4. For the 31-year-old the motivation is simple.

"It's [playing in Japan] something I always dreamed of when I was little," he said. 

"Especially now, with the Covid situation, if I can win as many as I can, I think it will bring better news, that's something I'm trying to do this week."

AUGER-ALIASSIME FAILS TO MAKE MOST OF MURRAY ABSENCE

Auger-Aliassime was scheduled to face Murray before the Team GB star pulled out with a quad issue and will instead focus on doubles.

The Canadian was felled by Murray's replacement Max Purcell, though, the Australian winning 6-4 7-6 (7-2).

Fellow seed Gael Monfils also crashed out but Hurkacz was a 6-2 6-4 victor over Luke Saville, while Diego Schwartzman also made it through.