Maria Sharapova's positive drugs test came as a shock to Chris Evert, but the American is unsurprised that tennis is part of a wider problem in sport.
The Russian former world number one sent shockwaves through tennis when she announced that she had failed a drugs test at this year's Australian Open.
Sharapova said she had been taking meldonium for the past 10 years for medical reasons and did not know that the World Anti-Doping Agency (WADA) had prohibited its use in January.
"I think you'd have to have your head in the sand if you didn't at least assume in every professional sport there might be some sort of PED being used," Evert told a news conference.
"Honestly, in every professional sport I think this goes on to a certain extent. In tennis it doesn't worry me as much. This went on when I was playing.
"I know players on the women's tour who were using PEDs and we didn't even have drug testing. I think it happens in every professional sport."
Evert, an 18-time grand-slam champion, said evidence from Sharapova's doctors would prove crucial in determining the length of the ban.
The 61-year-old believes a suspension until year's end may be enough.
"It all comes down to viewing the medical records from the doctors that took care of her 10 years ago and examining exactly what her case is," Evert said.
"This drug is used for angina and severe heart issues. There's always suspicion when you hear what the drug is used for. That's why her defence needs to show medical records, and dosage.
"If it does come out cleanly, I would say banning her for the rest of year would be enough."