IT says something about the women's singles at this year's US Open that the main talking points in the run-up to the tournament concern two players who aren't participating, Maria Sharapova and Wimbledon champion Marion Bartoli.

For all that Serena Williams can expect a renewed challenge from Viktoria Azarenka - last year's beaten finalist, and her nemesis in Cincinnati last Sunday - there remains the feeling that the 31-year-old from Palm Beach Gardens need only turn up to retain her title.

Bartoli shocked the tennis world when she tearfully retired at the age of 28 just weeks after winning her maiden Grand Slam title at Wimbledon. Sharapova, meanwhile, pulled out with a shoulder injury after a riotous few weeks in which her father, Yuri, sacked coach Jimmy Connors after just one match and the world No 3 abandoned plans to change her name to Sugarpova - her brand of sweets - for the duration of the New York event.

Bartoli has called a press conference today which may or may not see her backtrack, but Chris Evert, the six-times US Open champion turned ESPN pundit, doesn't feel the Frenchwoman, the subject of unflattering comments from BBC commentator John Inverdale during Wimbledon, is likely to change her mind.

"I don't think we're going to see her back," Evert said. "She's had a gruelling last 10 years. Because she's not the most natural athlete out there, I think she's had to work harder than a lot of the other players."

As for the split between Sharapova and Connors, Evert, once engaged to the latter, said: "Only Jimmy and Maria know what happened, but I can understand 100% her decision to try to change coach. I had a couple of coaching changes and then beat Martina Navratilova on grass at Wimbledon all of a sudden, which I hadn't done before. Players can get stale in their game and in their relationships with their coaches so, I don't think it's a bad idea, although it's not going to succeed every time."

As for those players who will be playing in Flushing Meadows, Evert feels Li Na and Sam Stosur, a former winner here, could be in the mix alongside Williams and No 2-ranked Azarenka. Emerging US players such as Sloane Stephens and Madison Keys could also be ones to watch.

"I consider Azarenka a legitimate contender, especially since she had Serena 5-3 in the third in last year's US Open final," Evert said. "But I think with Serena, a loss like Cincinnati just makes her more eager, more determined. As she said herself, she's a better player when she gets mad at herself. When she gets too calm, she gets a little complacent.

"But Viktoria is the one player who doesn't fear Serena: she is like a street fighter out there and hard courts are her best surface. It's too soon to tell whether that is a real rivalry, but I think it's going to make for a more interesting US Open."

Another point of interest will be to see how Laura Robson fares on her return to the venue where she last year became the first British woman to reach the fourth round of a major tournament since 1998.

This time around, she is already the first British woman since 1987 to earn a seeding - 31st - at a major. Her stock has never been so high, with the 19-year-old fast becoming one of the leading younger lights on the WTA tour.

That has been illustrated by management group IMG, who have recently lost Roger Federer but still look after the likes of Novak Djokovic and Sharapova, taking her on.

Robson's run here last year is well remembered - she beat former champions Kim Clijsters and Li Na - and her profile was given a further boost when she was mentioned on Twitter by Harry Styles of boy band One Direction during Wimbledon. Robson, back in action after injury and ready to face Spain's world No 53 Lourdes Dominguez Lino in round one, knows she's been making waves because of the reaction on the streets here.

"I've had a couple of random looks just, like, walking around Manhattan. Maybe they are British tourists. They don't really say hi, they just stare, which is a bit awkward," she said.

"We were walking past the queue for the One Direction concert. A couple of them were, like, 'Oh my God, you're the one that Harry tweeted'. So, yeah, I don't think they know my name or anything, it's just, like, that's how they know me."

On last year's successes, Robson added: "I had a couple of big wins. It really gave me a lot of confidence going into other matches against top players as I was thinking, 'I can beat them'. I felt I played really well for the rest of the year. I've always been someone who steadily improves, and I'm still going that way, hopefully."

Stewart Fisher and Steve Brenner