Chris Evert has expressed surprise at the lack of support within tennis for Maria Sharapova.
Women's tennis' most bankable star made the stunning announcement on Monday that she had failed a drug test for meldonium at the Australian Open.
The predominant response has been shock at how one of tennis' most professional and meticulous players could fail to take notice of warnings that a drug she had been taking for 10 years had been added to the banned list.
There have been some messages of support, with Sharapova's great rival Serena Williams praising her courage in taking responsibility for her mistake.
But others have been less charitable. Three-time grand slam champion Jennifer Capriati wrote on Twitter: "I had to lose my career and never opted to cheat, no matter what. I had to throw in the towel and suffer.
"I didn't have the high priced team of drs that found a way for me to cheat and get around the system and wait for science to catch up."
Evert, who won 18 grand slam singles titles, told ESPN: "Maria Sharapova has always isolated herself from the rest of the tennis world. She's made that known, she can't be friends with the players.
"I'm not seeing a lot of support from a lot of the players. I think everyone is being mum right now.
"Whether it's shock or whether they don't want to become involved or have an opinion about it, it's sort of surprising that not a lot of players have shown their support for her."
Sharapova has accepted a provisional suspension and will find out after a tribunal hearing in due course what sanction she faces.
The Russian admitted she received a link to the list of banned substances for 2016 in December but did not click on it.
Evert said: "It's just incredulous to me because she has such a very comprehensive and a very professional team. For everybody in the tennis world, Maria Sharapova is the last person we'd expect this to happen to.
"To me, it's a good warning to all the superstars out there that they mean serious business and that the sport is not protecting you if you're bringing in money for the sport, if you're bringing in TV ratings - it doesn't matter who you are."
The Russian has seen major sponsors Nike, Tag Heuer and Porsche all quickly distance themselves from her.
Sharapova, the world's highest-earning female athlete for the last 11 years, faces losing a large chunk of her income but skincare company Supergoop is standing by her.
Sharapova signed a deal to be the face of the brand, which focuses on sun safety, in 2014 as well as becoming co-owner with founder Holly Thaggard.
Thaggard said in a statement: "While we are surprised and disheartened by Maria Sharapova's recent announcement, we value our relationship with her as a co-owner of Supergoop! and ambassador for our common cause of conquering the epidemic of skin cancer.
"We appreciate Maria's candour and will continue to support her as the ITF investigation unfolds."
The International Tennis Federation, meanwhile, confirmed that Sharapova missed five opportunities in December alone to learn that meldonium had become a banned substance.
Documents detailing the prohibited substances for 2016 were distributed to players on December 3 and posted on the ITF website four days later.
On December 11 the WTA notified players that the documents were available while the ITF provided players with a link to them on December 22 - the one Sharapova failed to click on.
Then on December 29, the WTA sent another reminder of the availability of the documents to players.
Sharapova said at her press conference that she had been prescribed meldonium for 10 years by her family doctor because of health issues such as an irregular heartbeat and a history of diabetes in her family.
It was put on the banned list by the World Anti-Doping Agency in 2016 due to "evidence of its use by athletes with the intention of enhancing performance".