Novak Djokovic, a winner of four of the last five majors, is the clear favorite to defend his title at the year's final major. But if he is slightly off his game, there are several other players who could swoop in and take advantage, most notably, of course, Rafael Nadal and Roger Federer. Here's a look at some of the contenders for the biggest titles this summer hard-court season.
Top Contenders
Novak Djokovic
After a scintillating Wimbledon victory, Djokovic is skipping Montreal to get some rest in before he hits the hard courts during the American summer swing. The No. 1-ranked player in the world, a winner of two majors already this season, will be favored every time he takes the court this summer. He'll be defending his title at the US Open this year after he defeated Juan Martin del Potro in straight sets during the 2018 final. Djokovic will be attempting to win his 17th major title, which would put him just one behind Rafael Nadal and three behind Roger Federer for the all-time record.
Rafael Nadal
Fresh off another Roland Garros title and a Wimbledon semifinal, Nadal will be looking to defend his title from Montreal last season when he beat Stefanos Tsitsipas to win the week. The Spaniard is the top seed at the event, and therefore the favorite after both Novak Djokovic and Roger Federer opted out of playing the tournament for rest. Looking ahead, Nadal has been a winner three times at the US Open (2011, 2013, 2017), making it his second-most successful major event. He should enter the hard-court season full of confidence, and that will only be bolstered if he goes back-to-back in Canada.
Roger Federer
Since Federer is opting to skip Montreal for some extra rest, he will have turned 38 years before he takes the court again to kick off his summer hard-court swing after a heartbreaking loss in a fifth-set tiebreak at the Wimbledon final against Novak Djokovic. The 20-time major winner has not been able to find his peak level of play at the US Open in recent years, with his last title at the event coming all the way back in 2008. Still, Federer is 19-2 on hard courts this season, so he's going to be favored in just about every possible matchup, with the exception of Novak Djokovic.
Dominic Thiem
Thiem, known for playing his best on clay courts, has been rising on hard courts of late. He captured the biggest hard-court title of his career earlier this season in Indian Wells, and lost in an epic five-set quarterfinal match with Rafael Nadal at the US Open in 2018. The 25-year-old Austrian has proven he has the game to beat the best players on the biggest stages. He'll be entering Montreal as the No. 2 seed after winning his third title of 2019 in Kitzbuhel on clay over the weekend.
Outside Contenders
Stefanos Tsitsipas
Tsitsipas broke through last season in Canada with an upset win over Novak Djokovic and a run all the way to the final. The 20-year-old from Greece has vaulted inside the top 10 and has an excellent 37-16 record on the year along with two titles. He's never made it beyond the second round of the US Open, but he should advance much further than that this season. Deep runs in New York and the other hard-court events leading up to the year's final major are certainly plausible.
Felix Auger-Aliassime
Auger-Aliassime, who started the season outside the top 100, has vaulted to near the top 20 after a strong 2019 season so far in which he's gone 28-16. The 18-year-old Canadian has established himself as potentially the most promising prospect of any youngster on the men's tour, and based on his quick rise up the rankings this season, it's quite possible that it's only a matter of time until he breaks through on the Grand Slam stage.
Nick Kyrgios
The 24-year-old Australian, fresh off a week in Washington in which he knocked off two top 10 opponents en route to his second title of the year, is impossible to predict, but he's shown in spurts this year that he is one of the best players in the world when he turns on his game and focuses. Kyrgios has never advanced past the third round at the US Open, and hasn't reached a quarterfinal stage at a Grand Slam since 2015. It wouldn't be wise to expect much from him at the year's final major, but he's clearly capable of competing with the best in the world.
Daniil Medvedev
Medvedev, a winner of one title so far this season, has been extremely consistent with a record of 34-15 after a runner-up finish in Washington. His excellent season has pushed him inside the top 10 and he's at his best on hard courts, but has never advanced past the third round at the US Open. Depending on his draw, look for the 23-year-old Russian to be a threat to make his first major quarterfinal in New York.
Diego Schwartzman
Schwartzman, who has Grand Slam quarterfinal appearances in both 2017 and 2018, has yet to reach that stage at a major event this year, but he started off the summer hard-court season perfectly as he captured his third-career title in Los Cabos. The 26-year-old Argentine has previously reached the quarters at the US Open in 2017, so he's comfortable on American hard courts. At 27-16 on the year, he'll be a dark-horse candidate to make the second week at the year's final major, depending on his draw.