Nick Kyrgios says the high-profile doping cases involving Grand Slam winners Jannik Sinner and Iga Swiatek are "disgusting" for tennis.
Italian men's world number one Sinner still faces the threat of a possible suspension after he twice tested positive for an anabolic steroid in March.
Swiatek, also 23, served a one-month suspension after testing positive for a banned heart medication in August, when the Pole was women's world number one.
"I just think that it's been handled horrifically in our sport," said Australian Kyrgios, 29.
"Two world number ones both getting done for doping is disgusting for our sport.