U.S. Open tennis preview

Defending champs Djokovic, Osaka perched at top

Novak Djokovic (No. 1 seed), Serbia: He's the biggest of the men's Big Three right now, having won the Australian Open and Wimbledon this season and one other ATP title. He fought off match points in the fifth set against Roger Federer at Wimbledon, solidifying his status as the greatest defensive player of all time. He lost last week in the semifinals at Cincinnati to Daniil Medvedev. Djokovic is the defending Open champion and a clear favorite as he goes for the second three-Slam season of his career.

Rafael Nadal (2), Spain: Nadal won the French Open. So what else is new? He beat Djokovic in the final at Rome but surprisingly didn't win another clay court tournament. But he did win on the hard court at Montreal two weeks ago over Medvedev. Deciding to rest his hard-worn 33-year-old body, he pulled out of Cincinnati last week. He's likely to go deep into the second week, but does he have enough stamina now to make it to the end on a tricky knee?

Roger Federer (3), Switzerland: The Fed Express is 38 years old now and still humming along, having won three times this season. But holding two match points against Djokovic in the Wimbledon final, he lost them and eventually the match. It was crushing at the time, but this is the sport's all-time great so he can't be ruled out at Flushing Meadows, where stunningly he has not won since 2008. The last of his 20 record major victories was at the Australian in 2018. He rather woefully lost in the second round to Andrey Rublev in Cincinnati recently, but what the heck, the time off might do him good.

Daniil Medvedev (5), Russia: If there ever was a player riding a tidal wave of momentum, it's Medvedev, the 23-year-old Russian who is definitely one of the game's bright lights. He defeated Djokovic in the semis at Cincinnati and beat David Goffin in the final. The week before that he lost to Nadal in the final at Montreal. The week before that he lost to Nick Kyrgios in the final at Washington. He's jumped up to No. 5 in the world and will be extremely dangerous during this fortnight.

Alexander Zverev (6), Germany: There is no doubt that 22-year-old Zverev has enormous talent. But when will it all come together in a major? He's never made it past the quarterfinals of any Grand Slam, and the third round is his best at the Open. But at 6-6 with a big wingspan, big serve and big strides for court coverage, he should be built for Flushing Meadows. There have been off-court issues with his agent and with his coach Ivan Lendl. If things have reconciled, the No. 6 player in the world could be on the upswing.

Other top eight seeds: 4. Dominic Thiem, Austria; 7. Kei Nishikori, Japan; 8. Stefanos Tsitsipas, Greece

Ashleigh Barty (2), Australia: This has been a breakthrough year for the 23-year-old who currently is the No. 2 player in the world. She fought through a tough draw to win the Miami Open in March, and in June won her first Grand Slam title at the French Open. She won a grass court event in Birmingham, England, leading up to Wimbledon, where she then lost to American Alison Riske in the Round of 16. She lost in the semifinals to Svetlana Kuznetsova last week at Cincinnati, but it's been a fairly quiet summer and she should be well rested for the Open.

Simona Halep (4), Romania: The 2018 French Open champion's victory in the final at Wimbledon in July was a stunner, given that she handily defeated Williams 6-2, 6-2. That is her only victory this season but she has gone deep in a number of events while fighting a persistent Achilles heel problem. Her best finish in the Open was a semifinal loss in 2015. As the No. 1 seed she was bounced in the first round of the Open by Kaia Kanepi last year. Maybe she's due.

Serena Williams (8), United States: When we last left her at the U.S. Open she was involved in a raucous argument with the chair umpire that led to code violations and ultimately to her loss to Osaka in the final. Since then she has failed to win a tournament (lost to Halep in the Wimbledon final), pulled out of others with injuries (including last week at Cincinnati with a bad back) and thus is a question mark at this U.S. Open. She is still in hot pursuit of a 24th Grand Slam title. With a day off between matches at this Slam, the soon-to-be 37-year-old might get sufficient rest to make another run. And, as always, she remains the player to watch.

Madison Keys (10), United States: The tennis world has been waiting for this 24-year-old to grab a Grand Slam victory. In the only final she has reached, she was beaten by friend and fellow American Sloane Stephens in the 2017 Open. Now she is coming off an impressive run to the championship at Cincinnati last week, beating in succession Garbine Muguruza, Daria Kasatkina, Halep, Venus Williams, Sofia Kenin and Kuznetsova. She also won at Charleston in April. Confidence has been an issue, but Keys should be in high gear for this Open.

Other top eight seeds: 3. Karolina Pliskova, Czech Republic; 5. Elina Svitolina, Ukraine; 6. Petra Kvitova, Czech Republic; 7. Kiki Bertens, Netherlands