With no Roger Federer and no Rafael Nadal on the men's side, and no Serena Williams and no Venus Williams on the women's side, this year's US Open will have a little bit of a different feel. But Novak Djokovic is still in it, and he's eyeing that elusive calendar Grand Slam. Naomi Osaka is competing in her first Slam since withdrawing from the French Open earlier this year.

So which players are worth tracking? And which players actually have a shot to upset Djokovic en route to history? Our tennis experts make their predictions for this year's tournament.

If not Djokovic, who will win the men's singles title and why?

James Blake: Daniil Medvedev is playing so well right now. The court speed should suit his style and will probably be similar to Cincinnati.

Bill Connelly: Medvedev. He's 38-5 on hard courts since November (and 8-1 since the Olympics), and he has to beat only one of Djokovic and Alexander Zverev. Seems like an awfully favorable combination.

Cliff Drysdale:  Medvedev. There are three others close, but he is confident and playing on his most loved hard courts.

Chris Evert: I really don't see anyone but Djokovic, because he's come this far, had some rest, and he's not going to let this opportunity for history slip. He is the toughest mentally and confidence-wise.

Brad Gilbert: Though I would love to see that perfect game form Djokovic and first calendar slam in the men's game since Rod Laver in 1969, I think Medvedev, Stefanos Tsitsipas and Zverev will all be in later rounds that Djoker will have to go through.

Jason Goodall: Either Medvedev or Zverev. Medvedev excels at this stage of the season, loves the speedy hard courts of North America, and has played very well of late. He was a little tired in Cincinnati, but played well enough across the two ATP 1000s both there and in Canada where he won. For Zverev, his gold-medal winning performance in Tokyo could prove to be the catalyst for Grand Slam glory, as it did for Andy Murray in 2012, if he can continue to serve effectively.

Sam Gore: Before I answer, let me be a reminder that very few players in the history of the game have faced the pressure Djokovic is about to face. No man has won a Calendar Slam since 1969 and on top of that, if he wins the US Open, he would also pass Federer and Nadal atop the men's all time major singles titles list. Wow! So ... will Djokovic consider this pressure as a privilege, or will it be too much?

If he doesn't win, I'm going with Medvedev. He has been on-site all week, pushing himself in 90-degree heat at least twice a day. He also said when he got to New York, "We're here to not let [Djokovic] win the US Open." With a mentality like that, and someone who loves to play in front of the crowds at the Open, not to mention his incredible past hard-court results, he's my non-Djokovic pick.

Luke Jensen: Zverev is on fire! Players coming into a major with big wins always grab my attention. Winning in Tokyo and Cincinnati is impressive. Dude reached the finals of the USO 2020 and had a two-sets-to-love lead in the final. He seems to have mentally reached another level that will be the difference when the pressure gets tough.

Aishwarya Kumar: Zverev. He's coming off of a great year, winning the Olympic gold medal in Tokyo. Let's also not forget that he already knows what it's like to lose at a US Open final -- last year he lost to Dominic Thiem, who will not defend his title owing to an injury. Aside from Djokovic, who he will meet in the semifinals if all goes according to plan, Zverev will have an easier outing this tournament when compared to the previous years after withdrawals from Rafael Nadal and Roger Federer.

D'Arcy Maine: Medvedev. He has experience and momentum on his side, having previously reached two hard-court major finals and having taken home the title in Toronto earlier this month. Not to mention, as evidenced by his time in New York in 2019, Medvedev thrives on the crowd, and with 100% capacity expected, this could be his time to win. And as Djokovic hasn't had the best luck at the US Open over the past two years and hasn't played since his meltdown at the Olympics, Medvedev winning it all might not be as far-fetched as some are thinking.

Patrick McEnroe: Medvedev gets his first major. It's time. Djoker gets close but can't quite close it.

Pam Shriver: The field. Obviously Djokovic is the favorite to win the first men's Grand Slam since Laver in 1969, but I keep flashing back to Serena going for the Grand Slam in 2015 and being outplayed in the semis by Robertà Vinci. I also play back Djokovic's meltdown at last year's US Open, resulting in him being defaulted, and his outbursts during the Olympics especially in the bronze medal match.

Rennae Stubbs: Medvedev. He has been so close at hard-court slams, so he is the next best in my opinion.

Ohm Youngmisuk: The first thing going for Medvedev is that he's on the right side of the bracket -- away from Djokovic. The 2019 runner-up comes into the Open having won in Toronto and reaching the semis in Cincinnati. Medvedev has now reached two Slam finals and he has the consistency and game to frustrate many top players, especially in the type of sticky heat here at the Open, to finally break through.

Who will win the women's singles title and why?

Blake: Ash Barty is having an incredible year and I don't see any reason for it to stop.

Connelly: Barty. It feels like she and Naomi Osaka are a step ahead of the field on hard courts, and while Osaka has won the past two hard-court Slams, Barty's obviously the more in-form player at the moment, having lost just once in the past three months. (This reminds me that we've only had one Osaka-Barty match on hard courts in the past three years. Those two playing in the finals would be absolutely dynamite.)

Drysdale: Osaka. If she comes to terms with her anxiety, she has the most talent in the field.

Evert: Naomi, because she loves the Open after winning it, she excels on hard courts, which all her majors have been won on, and she's fresh and feeling more comfortable with herself and her game after some time off reflecting

Gilbert: Normally, I'd say 20-30 women can win it, but not the case here. Maybe four or five can win, but I will go Barty. I like the way she is playing and looks ready to win her second straight.

Goodall: Barty is the favorite for good reason: Her form this season, particularly this summer, has been the best of her career. However, Osaka is a better hard-court player when confident and playing well. When both are at the very top of their games, Osaka wins in these conditions. However, nobody really knows what to expect from Osaka given she has played such little tennis of late. She's good enough though to play herself into form throughout the tournament -- like Serena Williams has done in the past -- and if she's still in the hunt come semifinals, my money's on her.

Gore: Barty. This is her time and she's locked in. She's done very little press, as if she's determined to let her tennis do the talking. Having observed her here for about a week, she just seems to have another level of intensity and confidence right now.

Jensen: I have an extraordinary amount of confidence in Osaka. She plays amazing tennis in New York and on hard courts in general. This flies against my hot players arriving into a major theory, but Osaka has a super power to lock into her game and win.

Kumar: There's a clear answer: Barty. The World No. 1 from Australia has won five titles this year, including the two big tournaments leading up to the US Open -- Wimbledon and Cincinnati Open. She's 3,000 points ahead of the No. 2 ranked player in the world, Aryna Sabalenka. She has been handed a tricky draw, though. In the quarters, she might face French Open champion Iga Swiatek, followed by the 2019 US Open titleholder Bianca Andreescu in the semis. But Barty is having a great year, and I wouldn't put it past her to breeze her way into the finals where she might face two-time US Open champion Osaka for the title.

Maine: Barty. The world No. 1 has had an incredible season and has shown no signs of slowing down. Fresh off of her fifth title this year in Cincinnati, Barty looks more consistent and confident than ever. Provided she stays healthy and injury-free, she's the closest thing to a lock the women's game has seen at a major in some time.

McEnroe: Osaka finds her A-game and with huge crowd support she retains her title.

Pam Shriver: Barty, as finally another women's champion is comfortable playing with the No. 1 next to her name. Barty has handled the longest road trip of her career beautifully and is ready to add her third major to her resume.

Stubbs: Barty. The courts suit her and she is super confident right now. The slice works on this fast court, her serve is so tough to read and she has one of the best forehands in the game. She will go into this knowing how to win seven matches, how to handle the pressure and will keep her head down in this long trip to get herself another Slam.

Youngmisuk: With all that has happened this year since the French and Serena Williams not here, Osaka will be the clear fan favorite. And that could be what gets her back on track to finish this year strong. Osaka comes into the Open having lost in the fourth round in Cincinnati and the Olympics. And her quarter of the bracket isn't easy with a potential fourth-round meeting with Angelique Kerber or Coco Gauff and possible quarterfinal match against either Elina Svitolina or Simona Halep. But she has won her past 14 matches at hard-court majors, and these tough tests on her side of the draw could get her game going again with the full backing of the crowd.

Which men's player currently ranked outside the top 10 could make a surprise run to win and why?

Blake: Hubert Hurkacz can have a run here. He excelled early in the year in the states on hard courts and proved to himself he can beat a legend at a Slam at Wimbledon.

Connelly: Pablo Carreno Busta would be the obvious choice -- he has reached the US Open semis twice, and he only barely qualifies for this list (he's currently No. 12) -- but his draw could be absolutely brutal: He could play Seb Korda in the second round, Reilly Opelka in the third and Karen Khachanov/Denis Shapovalov in the fourth before potentially having to beat Zverev, Djokovic and Medvedev. Yikes. If you're looking for a good hard-courter with a kinder draw, then perhaps Felix Auger-Aliassime fits the bill.

Drydale: Jannik Sinner, he has a good hard-court game. Like Djokovic, he is equally strong on defense and offense.

Evert: Opelka for a surprise because of his unreturnable serve, his quick movement for a big guy, and his growing confidence in winning big matches.

Gilbert: I would really like to see an American man potentially make the quarters, maybe Opelka or John Isner.

Goodall: Hurkacz. He loves playing in North America and his win in Miami earlier this season at the ATP 1000 in similar conditions will have given him a huge boost of confidence, and as a result he will believe he belongs at the tail end of the majors and can go deep here, especially having done so at Wimbledon. As far as the Americans go, I'd love to see Jenson Brooksby get in among the big boys here. His game is unique and he seems to understand exactly what's required to win on any given day, so even though he's lacking in experience at this level it wouldn't surprise me if he stepped up and made a run.

Gore: Call me a dreamer, but that's OK! I'm going with Isner. The courts are playing lightning fast and if he serves well, this could be the year no one has an answer.

Jensen: Mackie McDonald. This former NCAA champion from UCLA is tough, and I mean tennis-genius tough. Smart players always impress me, and McDonald has had a great summer, reaching the finals in Washington. Dude has sneaky-good power and applies tactical pressure while moving forward with confidence.

Kumar: I'm going to go with Kachanov. He had a blistering run at the Tokyo Olympics, winning the silver medal, and had his personal-best Wimbledon finish this year, making a quarterfinal appearance. He could absolutely take down some of the top seeds en route to Week 2.

Maine: Hurkacz. He was the surprise champion in Miami (his second of two hard-court titles this year) and reached the semifinals at Wimbledon with wins over Medvedev and Federer. He doesn't have the most favorable of draws and could face Djokovic in the quarters, but Hurkacz doesn't seem to get intimidated by the moment -- or the opponent -- and would have a real chance to pull off that upset.

McEnroe: Reilly Opelka makes his best run yet in a major.

Pam Shriver: An American male. You can not be serious that it's been 18 years since an American man has made a major final, much less win one. I don't know which USA man, but it's time for another breakthrough at a major.

Stubbs: Opelka. He's playing great, is super confident and will have the fans right behind him.

Youngmisuk: Sinner might be the future of men's tennis. With legends like Federer and Nadal out, the Italian has an opportunity to emerge in this Open. Sinner, who just turned 20, won in Washington in early August, overcoming the kind of heat and humidity that could test the players over the next two weeks. Sinner could give fourth-seeded Zverev plenty to handle in their quarter of the draw.

Which women's player currently ranked outside the top 10 could make a surprise run to win and why?

Blake: Elise Mertens. She isn't normally someone who seems poised for a breakout because she is usually just consistent. But with faster courts, I think she can succeed.

Connelly: She hasn't had the luck of the draw of late -- she has had to play either Barty or Aryna Sabalenka before the semifinals of her past three hard-court tournaments -- but Victoria Azarenka is 23-6 over the past year or so on hard courts, and she reached the US Open finals a year ago. She might have to get past Garbine Muguruza in the third round, but the draw could be worse.

Drysdale: Halep. She has a great coach and is ready for battle after time off.

Evert: Maria Sakkari has had a good run this year. She's physically fit, and firmly believes she can beat anyone in the field. She came close at the French, reaching the semifinals, and won the Canadian, and she is primed and building.

Gilbert: I think an unseeded player makes the semis, and it will potentially be a young player, 21 and under.

Goodall: Your guess is as good as mine. Coco. Why not?

Gore: The winner of the Sloane Stephens-Madison Keys first-round match. Can you believe a first-round match was once a US Open final? Those two this year are underdogs, but they know how to navigate the draw and the chaos of the Open. They are both capable of going all the way to the final.

Jensen: I like the former two-time NCAA singles champion from Virginia, Danielle Collins, because she is an elite fighter. She is fearless and every player in the draw won't enjoy seeing this big-time American with two singles titles this summer on the other side of the net.

Kumar: Never rule out Halep. Two-time Grand Slam champion and this year's French Open finalist, Halep is always a threat, especially when the attention is not on her. And the fact that she has never won the US Open will only fuel her more.

Maine: Jil Teichmann. Sure, this very much could be recency bias talking here, but the 24-year-old beat reigning US Open champion Osaka, Olympic gold medalist Belinda Bencic and 2021 Wimbledon finalist Karolina Pliskova over the course of three days en route to the Cincinnati final. She has never advanced past the second round at a major before, but in the world of the WTA, when has a little inexperience ever stopped someone before? With two other top-10 victories this season, she has proved she's more than capable of beating anyone.

McEnroe: Ons Jabeur uses her eclectic game to light it up and go deep.

Pam Shriver: Outsider Coco Gauff is ready to welcome US Open crowds back and take her maturing game to a high level in New York. If her forehand and serve hold up, she is a threat to win her first singles major.

Stubbs: Collins. Like Opelka, she will use the crowd, the home-court advantage and have a great run.

Youngmisuk: Gauff could face either Stephens or Keys in the second round followed by Angelique Kerber potentially in the third round. And Osaka could be waiting in the fourth round. Without a doubt, Gauff will have to earn her way to the quarters, but if she survives those kind of matches, Gauff will be on the kind of roll that can win the Open. And she will have the backing of the Open crowd as well.