Novak Djokovic was not at his best to start his US Open title defence, but still eased beyond Radu Albot in straight sets.

Djokovic, who is hunting his first grand slam title of the year on the back of claiming Olympic gold in Paris, won 6-2 6-2 6-4 on Sunday.

However, Djokovic was not at his best, making 40 unforced errors and 10 double faults.

"I wanted to kick start the tournament in the right way and I think I did," Djokovic told ESPN.

"Some ups and downs which I think is normal, getting the rust off your shoulders coming off a different surface and the Olympic Games.

"I haven't played on hard courts for six months, so I'm still finding that groove, finding the tempo on the court."

Next up for Djokovic, who would claim his 100th Tour-level title should he triumph in New York, is his compatriot Laslo Djere, who defeated Jan-Lennard Struff.

Data Debrief: Djokovic equals Federer

Only the great Jimmy Connors (98) has won more US Open singles matches than Djokovic, who claimed his 89th victory at Flushing Meadows to match Roger Federer's tally.

This was also Djokovic's 78th win at Arthur Ashe Stadium, a competition record for a male player.

Dominic Thiem's grand slam career ended in the first round of the US Open in a straight-sets defeat to Ben Shelton on Monday.

Thiem won his sole major at Flushing Meadows in 2020, coming from two sets down to beat Alexander Zverev with no crowd present due to the Covid-19 pandemic.

In what turned out to be his final appearance at a grand slam, Shelton cruised to a 6-4 6-2 6-2 victory, before the American led the crowd in a standing ovation for Thiem.

The Austrian has struggled with a wrist injury in recent years, and announced in May that he would be retiring at the end of the 2024 tour.

Thiem was the first Austrian player in the Open Era to receive a wildcard for the men's singles at the US Open, and the first to receive wildcards to multiple grand slam events after last year’s Australian Open

"It's actually a really important moment for me because I had my greatest success of my career here on this court, in a weird 2020 in very strange and different circumstances," Thiem told the crowd.

"I'm super happy that I got the chance to play my last US Open and I can spend some time with you guys, just to say thank you and to make the time up from what we missed four years ago."

Elsewhere, fourth seed Zverev, Andrey Rublev and 2022 finalist Casper Ruud were among the winners in the first round in New York.

Defending champion Coco Gauff stormed into the second round of the US Open with a comfortable straight-sets win over Varvara Gracheva on Monday.

The 20-year-old only needed 67 minutes to see off the Frenchwoman 6-2 6-0 at Arthur Ashe Stadium.

Gracheva started brightly, serving to love in the first game and twice came close to breaking Gauff's serve in the second before the American finally found her footing.

Gauff got two breaks shortly after, going on a three-game winning run to take the first set.

She was in cruise control in the second though, comfortably seeing off Gracheva without dropping a game as she set up a second-round meeting with Tatiana Maria.

Elsewhere, Olympic gold medallist Qinwen Zheng had to come from behind to beat Amanda Anisimova.

After losing the first set, the seventh seed rallied to win 4-6 6-4 6-2, gaining control of the match in the decider to book a place in the next round.  

Data Debrief: Gauff sends out statement

Gauff won her first grand slam title at Flushing Meadows last year, becoming the first American teenager to win the US Open since Serena Williams in 1999.

And she is now the youngest player to register eight consecutive wins at the tournament since Maria Sharapova who won nine between 2006-07.

Gauff is also the youngest player to secure 15 women's singles wins at the US Open since Caroline Wozniacki in 2010.

Novak Djokovic is hoping his Olympics success will spur him to US Open glory despite not playing since the Paris Games.

Djokovic became just the second player in the Open Era to win all four grand slams, the gold medal at the Olympics and the ATP Tour Finals after Andre Agassi.

The Serb triumphed at Flushing Meadows last year, winning his 24th major title, but one year on, is still waiting for the win that would take him clear of Margaret Court as the outright record holder.

He came close at Wimbledon but lost the final in straight sets to Carlos Alcaraz, who he then beat to claim his elusive gold medal earlier this month.

Djokovic, the number two seed for the tournament, will begin against Moldovan qualifier Radu Albot on Monday, and he believes his recent success will serve as the perfect springboard for a similar outcome in New York.

"I hope to never recover from that [Olympic triumph] because it's the best set of feelings that I ever had as an athlete," he told Eurosport.

"On the court but also off, when we went back to celebrate with our people, all of the Serbian Olympians that managed to win a medal.

"It was a very unique moment for me. I'll never forget it, and I'll try to use it as a great confidence boost for what's coming up in New York in the next few weeks."

At 87.1%, Djokovic holds the second-best win percentage at the US Open in the Open Era of players to have featured in at least 30 matches at the event, after Sampras (88.8%).

And the 37-year-old will be hoping that is a good omen as he aims to win a joint-record fifth title at the tournament.

Alcaraz and Jannik Sinner have split the major trophies between them so far in 2024, while the last time Djokovic failed to win a single grand slam in a calendar year was in 2017.

Djokovic has not competed in the hard-court swing so far, instead choosing to recover, having struggled with a knee injury since the French Open in May, but he is sure that break will help his performance.

"I haven't had much time to recover or much time to train," he added. "I tried to get the most out of the few weeks that I had.

"I had more than all the other guys that played the tournaments, but that was a conscious decision that I made not to have any lead-up tournaments to the US Open because I just felt that the calendar is too congested this year with the Olympics.

"I needed my break, short but sweet, celebration, family quality time and then, of course, [I] started my training and trying to build my body, build my form for the start of the tournament."

Carlos Alcaraz insists his recent ankle concern is nothing serious and that he will "be at 100%" for this year's US Open.

The Spaniard is seeking his second triumph at Flushing Meadows, where he was victorious two years ago, as well as a third major of the season following his success at the French Open and Wimbledon.

Although, there were briefly question marks over Alcaraz's participation in the year's final slam after he pulled out of practice on Friday with an ankle injury. 

Nevertheless, he said the reason for not continuing the session was precautionary above anything else.

"After a few hours after finishing my practice, I have not felt anything and everything is fine and under control," said Alcaraz, who begins his campaign against Li Tu on Wednesday "I think it is not going to be anything serious. 

"We will take care of it in the next few days and we will be extra cautious. I think it was just a scary moment, but I am sure I will be at 100%."

Alcaraz also reflected on his Olympic gold medal match against Novak Djokovic earlier this month, in which the Serb avenged his Wimbledon showpiece defeat to complete a career golden slam.

The Spaniard admitted it was a defeat that hurt, but made him more determined to go the extra step in four years' time.

"It was one of the most important finals of my career, my life," he said. "I know the Olympic Games is every four years, so I don't know if I'm going to have another chance to win the gold. I'm going fight for it, for sure, at the next Olympic Games.

"It was a difficult moment [for me to] deal with, losing the gold medal in a really close match when I had opportunities, but in front of me, I had a really good player that day.

"[Djokovic] was fighting for the same thing as me and he deserved it, and days after the Olympics, I realised that I won the silver medal. It was a great achievement for me."

Emma Raducanu says she is always ready to "do things a little bit differently" as she prepares for the US Open.

The 21-year-old is set to play just her second match at Flushing Meadows since winning the grand slam as a teenage qualifier in 2021.

She will face American Sofia Kenin in the first round, with Jessica Pegula a potential second-round opponent if she gets through.

Raducanu has only played one tournament since being knocked out in the fourth round at Wimbledon, opting to miss the Olympics, as she continues to ease herself back into regular action after her long injury lay-off.

She reached the quarter-finals in Washington, going out to eventual champion Paula Badosa, but chose not to play in Toronto before deciding against qualifying for Cincinnati.

"I really wanted to play in Toronto, especially because I was born there, but the turnaround was too tight for qualifying," she told BBC Sport.

"I would have had to play on Sunday, and I finished [in Washington] late Friday night, so flying there and adjusting, I just felt was too tight.

"Otherwise, I just always do things a little bit differently.

"[In Cincinnati] I would have pretty much had to wait around just for one tournament in qualies and then another week off before the US Open - so I think it was a better decision we all made to just go back and work on things there."

Meanwhile, Naomi Osaka is hoping familiar surroundings will help to boost her confidence after a tough run in 2024.

Since returning from a 15-month maternity break in January, Osaka has struggled to recapture her top form, and in her most recent outing in Cincinnati, she was knocked out in the second round of qualifying.

Having won the US Open in 2018 and 2020, the 26-year-old believes being back in the city she grew up in will help her find her footing.

"I feel like, throughout the year, I have had really hard matches, and it kind of dipped my confidence a little," Osaka told reporters on Saturday.

"I do think coming to this specific tournament helps me out. But also, whenever I step foot here, I don't really think about the two tournaments I won.

"I just think about how I felt when I was a kid, because I did grow up coming here, and I have such vivid memories of watching my favourite players. It's more of a childhood nostalgia that I really enjoy."

The final grand slam of the season is already upon us, with the US Open getting going on Monday.

Flushing Meadows will welcome the best and brightest as they aim to light up New York City, where home favourite Coco Gauff will be the defending women's singles champion.

She clinched her maiden major title at Arthur Ashe Stadium last year, overcoming Aryna Sabalenka 2-6 6-3 6-2.

Gauff will be the third seed at this year's tournament, with Sabalenka second and world number one – the fearsome Iga Swiatek – rated as the favourite.

With the help of Opta data, we look into the likely challengers for this year's title.

Will Swiatek cap stellar year?

Swiatek has won 55 matches in 2024, which is the most of any player on the WTA Tour. She also has the longest winning streak in Tour-level events this season, too, having reeled off 21 straight victories.

The all-conquering Pole has won six Tour-level events this term – the United Cup, Qatar Open, Indian Wells Open, Madrid Open, Italian Open and French Open. Unsurprisingly, Swiatek also has the best win percentage of any player across 2024 (88.7%, having lost just seven of her 62 matches).

Swiatek – who clinched bronze at the Paris Olympics – has won all six finals she has been involved in this term, becoming the third player this century after the Williams sisters to triumph in their first six finals of a season across multiple years (2022 and 2024).

The 23-year-old holds a record of 79-17 at grand slams, and the best winning percentage of any active player (82.3%). Among players to have started their career in the Open Era, only six players could achieve 80 wins in fewer major matches than Swiatek (97) – Monica Seles (86), Chris Evert (89), Martina Hingis (92), Serena Williams, Steffi Graf (93 each) and Venus Williams (94).

She will face qualifier Kamilla Rakhimova in the first round. Swiatek has won in straight sets in all her previous eight matches against qualifiers or lucky losers, while she is also undefeated in her five first-round ties at the US Open.

In fact, the last time Swiatek lost in the opening match of an event was at the WTA Finals 2021 in Guadalajara. She has played 48 tournaments since then without ever falling at the first hurdle (United Cup and Olympics included). 

Among current players with 10+ main draw matches played at the US Open, only Bianca Andreescu (85.7%) and Naomi Osaka (81.5%) have a higher winning percentage at Flushing Meadows than Swiatek (80.0%).

Sabalenka on song

Swiatek and Sabalenka tussled on the clay courts earlier in the season, but the latter has endured a difficult summer swing and had to skip the Olympics.

But she returned to form at the Cincinnati Open, triumphing over Jessica Pegula to claim her second title of the season.

Her first was the Australian Open, and that means Sabalenka could become the first woman to win both hard-court grand slams in the same year since Angelique Kerber in 2016. Indeed, since the Australian Open switched to hard court in 1988, the Belarusian could be the fifth woman to reach both hard-court major finals in successive seasons after Graf (1988-90, 1993-94), Seles (1991-92), Hingis (1997-99) and Victoria Azarenka (2012-13).

Like Swiatek, Sabalenka will take on a qualifier (Priscilla Hon) in round one. She won her previous meeting with Hon, back in Mumbai in 2017. The top two seeds will both face qualifiers in the first round of a grand slam for the first time since the Australian Open 1996 (Seles and Conchita Martinez).

Sabalenka is undefeated in her six first-round ties at Flushing Meadows, while she is aiming to be the fourth player in the Open Era to win the title in Cincinnati and New York in the same season, with Gauff having done just that last year.

Only Swiatek (25) and Emma Navarro (24) have won more hard-court matches than Sabalenka in 2024 (23), while the previous season's runner-up at the US Open has only lost in the first round on one occasion in the Open Era (Pam Shriver in 1979).

Gauff and Pegula the fan favourites

The Olympics ultimately ended in tears and frustration for Gauff, and after reaching the semi-finals of the Australian Open and French Open, her season is somewhat threatening to peter out. Indeed, her only title this year came in the first tournament of the campaign, in Auckland.

Yet as one of four American players since 2000 to win the singles title at the US Open, she will be fiercely determined to retain her crown at Flushing Meadows and will be backed by vociferous home support.

The world number three is not the only home favourite in with a firm chance, though.

Pegula won nine successive main-draw matches, equalling her longest career winning streak, across her campaigns at the Canadian Open and Cincinnati Open, before losing to Sabalenka in the final of the latter tournament.

The sixth seed could become only the fourth player in the Open Era to reach the singles finals at the Canadian Open, Cincinnati Open and US Open in a season after Rosemary Casals (1970), Evonne Goolagong Cawley (1973) and Serena Williams (2013).

The other contenders

Emma Raducanu has not had quite the hard-court swing she would have liked, but the youngster triumphed in New York as a teenager back in 2021, and will be one to keep an eye on.

Jasmine Paolini heads to Flushing Meadows fresh from claiming Olympic gold at Roland-Garros, where she also reached the French Open final earlier this year. The Italian has both hit the most winners (409) and converted the most break points (80) in singles matches at grand slams in 2024.

She will go up against 2019 US Open winner Bianca Andreescu in round one, making the duo the first players to face each other in the women's singles at Roland-Garros, Wimbledon and Flushing Meadows in the same season since Serena Williams and Justine Henin in 2007.

Elena Rybakina, meanwhile, has served the most aces (85) at majors this year.

Then there is two-time US Open champion Naomi Osaka. She will go up against Jelena Ostapenko, and combined with Sofia Kenin taking on Raducanu, it makes this tournament the first time that two former grand slam winners are taking each other on in first-round ties in New York since 2019.

When Novak Djokovic triumphed at Flushing Meadows last year, he surely thought the outright record for grand slam titles was all but his.

Yet just shy of a year later, Djokovic is still waiting for his 25th major win - and the one that would take him clear of Margaret Court, making him the undisputed greatest of all time.

He came close at Wimbledon, but Carlos Alcaraz ultimately had too much, with the Spaniard winning the final in straight sets.

Alcaraz, the 2022 US Open champion, will be one of the most likely candidates scrapping it out for Djokovic's crown over the next two weeks, along with world number one Jannik Sinner.

Djokovic avenged that Wimbledon defeat with a 7-6 (7-3) 7-6 (7-2) win over Alcaraz in the final of the Paris Olympics, with the 37-year-old ending his wait for a gold medal.

But while that gold is now hanging around his neck (or, in his trophy cabinet, which must be pretty big), it did not settle Djokovic's desire for that record-breaking major triumph. His next tournament win would also bring up his 100th career title.

Should Djokovic fail to defend his crown, though, it will be just the fourth year since he won his first major in 2008 that he has not won a grand slam in a season, after 2009, 2010 and 2017.

But what do the Opta statistics tell us about the key storylines ahead of the US Open?

Can Djokovic dominate?

Jimmy Connors, Pete Sampras and Roger Federer have won the US Open a joint-record five times each. Should Djokovic win, he will join that illustrious trio on five Flushing Meadows titles.

Connors has appeared in (115) and won (98) the most singles matches of any player in the Open Era at the tournament, but Djokovic (88) has won the most among active players and could equal Federer (89) for the second-most by defeating Radu Albot in round one on Monday.

Should Djokovic reach the second round, he will also match Federer's tally of matches played in the competition (103).

At 87.1%, Djokovic holds the second-best win percentage at the US Open in the Open Era of players to have featured in at least 30 matches at the event, after Sampras (88.8%).

The Serbian great, who became the oldest player to win the men's singles at the US Open when he succeeded at the age of 36 years and 111 days in 2023, has featured in the most men's singles finals in the tournament's history (10). He is the only player in the Open Era to have reached 10+ finals at multiple grand slams, having also done so at the Australian Open and Wimbledon.

Should he reach the quarter-finals, barring walkovers, Djokovic will surpass Federer (429) for the most matches played at grand slams in the Open Era. If he were to then reach the last four, he would be the first male to appear in 50 major semi-finals, and the second player overall after Chris Evert (52). 

Connors (109) and Federer (103) are the only players to win 100 Tour-level titles, while Djokovic is chasing his 72nd hard-court title, which would take him clear of Federer (71).

Could the kids have too much?

Djokovic may have outfought Alcaraz at the Olympics, but that was only after he had been dispatched by the world number three at the All-England Club.

Alcaraz, who said he had played his worst-ever tennis during a shock defeat to Gael Monfils at the Cincinnati Open earlier this month, could become only the third player in the Open Era to win the men's singles title at Roland-Garros, Wimbledon and the US Open in the same year after Rod Laver (1968) and Rafael Nadal (2010).

Aged 21 years and 126 days, he would also be the youngest man to win a singles title at three grand slams in a calendar year. He won his first major title at Flushing Meadows two years ago, and reached the semi-finals last season, losing to eventual runner-up Daniil Medvedev.

Then there is the world number one, and top seed, Sinner. The Italian was forced to miss the Olympics due to illness, but after going out in the last eight at the Canadian Open, he returned to form with a sensational run to triumph in Cincinnati.

That was his fourth title of the season. Excluding team events, Sinner (23 years, 23 days) could become the youngest player to win five ATP trophies on hard court in a calendar year since Andy Murray in 2009.

Since the Australian Open switched to hard court in 1988, Sinner could become only the fourth male to win that competition and US Open in the same year, after Mats Wilander (1988), Roger Federer (2004, 2006 and 2007) and Djokovic (2011, 2015 and 2023).

Sinner has now won three ATP 1000 hard-court titles in total. Across the past decade, only three players have won more Masters titles on the surface: Djokovic (17), Federer (seven) and Medvedev (five).

The last top seed to lose in their opening match at the US Open was Stefan Edberg, who lost to Alexander Volkov in 1990.

Indeed, the US Open is certainly not a tournament in which you can confidently say "expect the unexpected" when it comes to major shocks.

Only two top seeds in the Open Era have been eliminated in the first round of the men's singles – John Newcombe (1971) and Stefan Edberg (1990). Andre Agassi is the last first seed to not reach the second week at the event, losing to Arnaud Clement in straight sets back in 2000. 

Ons Jabeur has withdrawn from the US Open with a shoulder injury just days before the season's final grand slam gets under way.

Most recently, she featured at the Canadian Open in Toronto where she lost in straight sets to Naomi Osaka in the first round.

The Tunisian has been struggling with injuries all season, seeing her miss the Paris Olympics and tournaments in Washington and Cincinnati.

And, just hours after the draw for the US Open was made, the world number 17 decided that her shoulder injury will not allow her to compete at Flushing Meadows.

"I am truly sad to announce that my shoulder won’t recover in time for the US Open. I feel I need to give 100 % and today it's not possible yet," Jabeur wrote on Instagram.

"Life has ups and downs, but sometimes in the very negative moments we all need to find the positive in it. This year has been very tough for me, but I know somewhere the light is there.

"Always grateful for the unconditional support you all bring to me."

The 29-year-old will be replaced in the draw by Elise Mertens, who will become the number 33 seed.

Jabeur achieved her best grand slam result at the US Open, reaching the final in 2022, but lost in straight sets to Iga Swiatek.

She also came agonisingly close to a major title in two further final appearances at Wimbledon in 2022 and 2023.

Carlos Alcaraz will begin his bid for a third straight grand slam success against a qualifier at the US Open, while top seed Jannik Sinner will face Mackenzie McDonald in the first round.

Alcaraz won his fourth major title at Wimbledon in July, dominating Novak Djokovic in the final after also triumphing at the 2022 US Open, Wimbledon in 2023 and the French Open earlier this year.

Should the Spaniard progress through his first-round match, he could take on Botic van de Zandschulp in round two and Britain's Jack Draper in the third round.

Seeded third, Alcaraz could face world number one Sinner in the semi-finals, with the Italian starting his campaign against a home favourite in McDonald.

Sinner recently avoided a ban after twice testing positive for banned substance clostebol, with an independent tribunal finding he was inadvertently given the steroid in an over-the-counter spray by his physiotherapist Giacomo Naldi.

On the other side of the men's draw, Djokovic will also start against a qualifier as he bids to finally surpass Margaret Court's overall record of 24 grand slam titles.

Djokovic won his 24th major crown at the 2023 tournament at Flushing Meadows, beating Daniil Medvedev in straight sets in the final.

He has struggled to find top gear at this year's grand slams, though he did claim his first Olympic gold medal by beating Alcaraz in the showpiece match at Roland-Garros.

In the women's draw, top seed Iga Swiatek will start against a qualifier while Coco Gauff will open her title defence by taking on Varvara Gracheva, with a testing third-round date with Elina Svitolina potentially on the cards for the third-seeded American.

Aryna Sabalenka joins Swiatek in facing a qualifier first, while there is a tricky draw for 2021 US Open winner Emma Raducanu, who is set for her first Flushing Meadows appearance since 2022.

She will take on the United States' 2020 Australian Open winner Sofia Kenin, with the victor set to face another American in round two, in either Shelby Rogers or sixth seed Jessica Pegula. 

The first round of the US Open begins on Monday, with the women's singles final set for September 7 and the men's showpiece match taking place one day later.

John McEnroe believes Novak Djokovic's triumph at the Paris Olympics has separated him from the likes of Roger Federer and Rafael Nadal. 

Djokovic, who won gold at the Games against Carlos Alcaraz, is preparing for the US Open in a bid to claim a 25th grand slam title at Flushing Meadows. 

The Serbian's win at Roland-Garros saw him become only the second player in the Open Era to have won all four grand slams, the gold medal at the Olympics and the ATP Tour Finals, along with Andre Agassi.

He also became the oldest player to secure a gold medal in either the men’s or women’s Singles at the Games, since the sport’s reinstatement as an Olympic event in 1988.

Djokovic has won three US Open titles across his illustrious career, with his success over Daniil Medvedev in 2023 the last time he won a grand slam. 

That victory saw him move two ahead of Nadal as the player with the most grand slam titles, while also going four clear of the retired Federer in the process. 

The trio once had a two-decade-long stranglehold on the men's game, but the current world number two is the last man standing this year.

And McEnroe, who lined up alongside Djokovic in a practice match against Alcaraz and Agassi on Thursday, believes the Serbian has already assumed the greatest of all time status. 

"He's looking to sort of separate himself from Federer and Nadal, that's really is what it boils down to," said McEnroe. 

"He seems to have already done that in a way. He's won the Olympics, won everything, won more than those guys.

"To me, you’d have to ask him, but it (more success) is gravy. He sort of put himself there already."

Carlos Alcaraz is determined to put his emotional outburst during the Cincinnati Open behind him as he prepares for the start of the US Open next week.

The Spaniard has enjoyed an unforgettable three months, winning the French Open and Wimbledon back-to-back before earning the silver medal at the Olympics.

However, his return to hard court has not been so smooth as he suffered a shock defeat to Gael Monfils in the second round in Cincinnati last week.

After cruising through the first set, Alcaraz's match was delayed by rain with the second set tied at 6-6, and the Frenchman rallied to win the tie-break and the decider.

The world number three's frustration was evident during the match as he smashed his racquet on the court four times midway through the third set.

Alcaraz admitted he struggled to adapt to the court's surface but is ready to step up his preparation for the US Open to avoid the same issues.

"I couldn't play. Honestly, I'd been practising really well," Alcaraz said.

"The previous days, I was feeling great, hitting the ball clear, moving well. I don't know what happened.

"I don't know how I felt like this. I couldn't control myself.

"It's really difficult to find some good stuff from this match. So, I want to forget it and try to move on. I'll go to New York and try to practise well, get used to those courts."

Alcaraz won the first of his four grand slams at Flushing Meadows as a teenager during his breakout tournament.

While a third grand slam title of 2024 may be on his mind, Alcaraz is also targeting a different goal for the end of the year, as he aims to leapfrog Jannik Sinner and Novak Djokovic to become the world number one.

"I'm focused on going to every tournament, thinking about playing great tennis, doing a good result to get better in the race," Alcaraz added.

"Ending the year as number one is one of my main goals."

World number one Jannik Sinner has been "worn down physically and mentally" by an investigation into his positive tests for a banned substance, says his coach Darren Cahill.

In March, Australian Open champion Sinner twice tested positive for clostebol – a banned substance that can be used to build muscle mass.

However, an independent tribunal last week found he was inadvertently given the substance in an over-the-counter spray by his physiotherapist Giacomo Naldi.

Sinner has won ATP-level titles at Halle and Cincinnati since the positive tests, but he was eliminated from the French Open at the semi-final stage and only reached the last eight at Wimbledon.

He then missed the Paris Olympic Games after being diagnosed with tonsillitis, and Cahill feels it was no coincidence that he failed to hit top form while the probe was ongoing.

"I guess if you are not a Jannik fan, you may not see too much difference in what he has been doing the last few months because he has still been playing quite well," Cahill told ESPN.

"But if you are a Jannik fan, you would have seen a big change in his body language, his physicality on the court, his excitement to be on the court.

"He's struggled and I think it's worn him down physically and mentally. He got tonsillitis, which is the reason why he missed the Olympics."

Some have been critical of the decision to clear Sinner of any wrongdoing, with 2022 Wimbledon runner-up Nick Kyrgios particularly vocal in his reaction.

Kyrgios wrote on X it was "ridiculous" that Sinner had escaped a ban, saying the Italian deserved to be hit with a two-year suspension.

Former Wimbledon semi-finalist Denis Shapovalov also suggested the decision was at odds with other players receiving bans over similar incidents.

Cahill, however, is of the belief Sinner would never intentionally take a banned substance, adding: "I just want to stress that he's maybe the most professional young man that I have ever had the chance to work with. 

"He would never ever intentionally do anything, and he's in a situation that is incredibly unfortunate."

Jannik Sinner has been cleared after twice testing positive for a banned substance in March.

The world number one tested positive for low levels of a metabolite of clostebol – a steroid that can be used to build muscle mass – during Indian Wells.

Sinner was notified about the positive tests in April and was originally given a provisional suspension, but he successfully challenged it and was able to keep playing.

The Italian had been inadvertently contaminated by the substance from his physiotherapist, who had used an over-the-counter spray for a cut on his own hand before treating Sinner, the International Tennis Integrity Agency's (ITIA) investigation found.

The ITIA accepted the explanation that the contamination was not intentional, and the 23-year-old was cleared of all fault or negligence by an independent tribunal last week.

Sinner will still lose the ranking points won at Indian Wells, where he was beaten in the semi-finals by eventual champion Carlos Alcaraz.

"I will now put this challenging and deeply unfortunate period behind me," Sinner said in his statement.

"I will continue to do everything I can to ensure I continue to comply with the ITIA's anti-doping programme, and I have a team around me that are meticulous in their own compliance."

The ATP praised the work done by the ITIA during their investigation to get to the right outcomes about the Cincinnati Open winner.

"We are encouraged that no fault or negligence has been found on Jannik Sinner's part," the ATP posted on X.

"We would also like to acknowledge the robustness of the investigation process and independent evaluation of the facts under the Tennis Anti-Doping Programme (TADP), which has allowed him to continue competing.

"This has been a challenging matter for Jannik and his team and underscores the need for players and their entourages to take utmost care in the use of products or treatments. Integrity is paramount in our sport."

Sinner will next be in action at the US Open, which starts on August 26 in New York.

Jannik Sinner won his fifth ATP tour title of the season on Monday, beating Frances Tiafoe in straight sets to win the Cincinnati Open.

The world number one took one hour and 37 minutes to earn his 7-6 (7-4) 6-2 victory, having battled through back-to-back three-setters in order to reach the final.

Sinner has been hampered by a hip injury, picked up during the Madrid Open in May, but rallied to get past the Frenchman.

"It was a very difficult week, tough week. I'm very happy about today's match," Sinner said in his on-court interview.

"It was very tough mentally. Had such an amazing run here, and I tried to do my best today.

"We both were quite tired from yesterday. We both felt a lot of tension, but I'm very glad about [the] level I played today, especially in the important moments."

There was little to separate the two in the first set, as they matched each other all the way to a tie-break, with Sinner eventually pulling in front to take the lead.

The Italian then got a vital break in the first game of the second set, taking confidence as he edged in front.

Tiafoe kept up the fight though, and successfully defended match point three times in the penultimate game, but he could only delay the inevitable as Sinner served to love in the last to get his hands on the trophy.

"It has been a tough week, some ups and downs, which is normal to have," Sinner added. "But how I handled the very important moments in each match, I'm very happy.

"I'm very happy to be in a position where I am and just trying to keep going mentally, having this hunger to keep playing, and hopefully, I can show some good tennis also in New York."

Data Debrief: Golden touch

Sinner has won his 15th career ATP title from 19 finals, equalling Carlos Alcaraz and Lleyton Hewitt (19). Only Rafael Nadal (17) has won more from his first 19 ATP event finals in the Open Era.

It is also his third ATP Masters 1000 title on hard court. In the past decade, only three players have won more Masters titles on the surface - Novak Djokovic (17), Roger Federer (seven) and Daniil Medvedev (five).