MELBOURNE, Australia – Sloane Stephens and Victoria Azarenka share an agent and a home base in Los Angeles.
But the 13th-seeded American minced no words about her relationship with the two-time defending champion before Azarenka eliminated Stephens 6-3, 6-2 Monday to advance to the Round of 16 at the Australian Open.
"Non-existent," Stephens told reporters on Saturday.
The comment highlighted a cultural gap that seems, at least of late, to be growing wider in professional tennis: Women have a harder time staying friendly than men.
"What can I say?" says Nadia Petrova of Russia, who has ranked as high as No. 3 in singles and doubles. "Girls are girls. We always find something to fuss about."
The last 12 months have been fertile ground for publicly aired verbal spats on the WTA tour.
Last spring, Stephens called out No. 1 Serena Williams as a phony in a damaging ESPN the Magazinestory.
At Wimbledon, Maria Sharapova criticized Williams' presumed relationship with her not-yet divorced coach Patrick Mouratoglou following comments by Williams in a Rolling Stone article where she appeared to take swipes at Sharapova's 22-year-old boyfriend, Grigor Dimitov.
Then there was Williams' not-so-cryptic tweet after she lost to Stephens in the quarterfinals of last year's Australian Open. It read: "I made you."
"The women, you don't even see them practice together," American John Isner observed at Wimbledon. "It's weird.''
What's behind the growing Frenemy phenomenon – sometimes friends, sometimes enemies across the net – is complicated.
Many explain the bonding difficulties to gender-influenced social mores.
"It's harder for women emotionally to switch gears and compartmentalize an off-court friendship from an on-court rivalry," says ESPN's Pam Shriver.
"Guys are more simple, win or lose, they shake hands, go to the bar and have a beer," says Petrova. "That's it. Put it behind."
"It's just harder for the very top players to really be more friendly and intimate off the court," chimes in Bethanie Mattek-Sands of the USA. "I don't know if that's a sexist thing to say."
Nothing in the rulebook says players have to be best buddies in tennis or any sport. Yet camaraderie has never been a strong suit on the women's tour, according to several former players.
Friendships have become scarcer due to the high stakes of seven-figure tournament purses, multi-million dollar endorsements contracts and protective entourages.
Social media also contribute since knee-jerk reactions on Twitter or Facebook can go instantly viral -- paradoxically allowing players to be more connected but less intimate.
It wasn't always this way.
Last year, Hall of Famer Shriver stumbled upon a handwritten letter Chris Evert left her in the locker room after Shriver beat Evert for the first time following 17 losses.
It read in part: "Thank you for being a gracious winner. It showed character….Keep it up – we need you (as an American) to emerge and blossom….Chrissie."
Shriver says such a gesture seems inconceivable today.
Evert, a former No. 1 and 18-time major winner, agrees.
Evert said today's top pros operate with a layer of protectors. Plus, top-ranked singles players rarely play doubles (as Shriver and Martina Navratilova did), another chance to bond.
"It's harder to be friends," says Evert, who competed in the 1970s and 1980s and now commentates for ESPN.
"We had to reach out or it would have been very, very lonely," she says. "Today's players don't need to."
Evert remembers consoling her adversary Navratilova, and vice versa, in the locker room on Sundays later in their careers when all the other players were gone.
"Martina and I said hurtful things to each other as well," Evert says of the rival she faced a record 80 times. "But it wasn't on the Internet, on Twitter or Facebook. We only talked to written press. A lot of things never get out."
These days, players said, it's especially challenging to remain friendly as the stakes grow bigger.
In March 2012, Stephens gushed about Azarenka in a story on the website 10sballs.com.
"I love Vika," she was quoted as saying. "You could tell me she sucks toes – I wouldn't care."
Stephens' comments Saturday would suggest a major shift in tenor — not a surprise considering her year-over year jump in the rankings and the controversy that enveloped last year's Australian Open semifinal when the No. 2 Belarusian took a controversial medical time out at a crucial juncture and went on to win.
There's also this: WTA players tend to be younger than their male counterparts, which can contribute to a more "cut-throat" atmosphere, say top-ranked doubles players Bob and Mike Bryan, who both attended Stanford University.
"They hold grudges for long periods of time, it seems to me," says Bob.
"Maybe it's the species," says Mike.
Some see the chilly stares and locker room snubs as competitive posturing.
"Some of the girls try to keep their distance from other players because they want to have that status," says Uzbekistan-born American Varvara Lepchenko. "They want you to be afraid of them."
To be sure, the men's game has seen plenty of animosity, too.
The big four of American tennis a generation ago – Pete Sampras, Andre Agassi, Jim Courier and Michael Chang – were estranged combatants.
In the 1970s and 1980s, Jimmy Connors, John McEnroe, and Ivan Lendl shared a dislike that extended far beyond the confines of the court.
Today's stars – Roger Federer, Rafael Nadal, Novak Djokovic and Andy Murray – have been both surprisingly dominant and surprisingly congenial, even sharing opinions as periodic members of the ATP Tour's Player Council.
On Sunday, four-time Australian Open titlist Djokovic said it "used to be" challenging to separate competition from companionship, but no more.
"As soon as you step on the court, it's all business," the No. 2 Serb said after dismantling No. 15 seed Fabio Fognini of Italy in the fourth-round 6-3, 6-0, 6-2.
Former top-10 player Andrea Petkovic of Germany sees a double standard, and says looks can deceive.
"They are friendly with each other, but are they friends?" 40th-ranked Petkovic says of the Nadal, Djokovic, Murray and Federer. "They are not friends. They are not going out to dinner. Even if they hug each other at the court because they respect each other so much, they are not close."
She calls the gender differences overblown.
"I think it's a cliché that if there are 20 women in the locker room they must be fighting," she adds, noting that she has maintained close ties with top pros like fellow German Angelique Kerber and No. 2 Azarenka as her own fortunes have fluctuated due to injuries. "The men are fighting the same amount as we are fighting, but it never gets played up."
Evert says she's not sure how she would behave if she were playing now.
But here's a clue: On Sunday evening, a video clip of Stephens celebrating behind glass in a luxury suite just after Ana Ivanovic upset Williams went viral.
Tweeted Evert: "Wow, nothing sacred anymore..."