American tennis player Serena Williams is not pleased about getting more drug tests than her competitors. Williams expressed her opinion Tuesday after receiving another unannounced visit to test for performance-improving substances. Williams wrote on Twitter, ”And it’s that time of the day to get ‘randomly’ drug tested and only test Serena. Out of all the players it’s been proven I’m the one getting tested the most. Discrimination? I think so. In another tweet, Williams wrote, ‘But I’m ready to do whatever it takes to have a clean sport so bring it on. I’m excited.’ It is not the first time this year that Williams has complained about being drug-tested more than other American players. Last month, she told reporters ahead of the Wimbledon tennis tournament, “Just test everyone equally.” Williams made it to the Wimbledon final, where she lost to Germany’s Angelique Kerber. A report in June by the news site Deadspin found that Williams had been drug tested five times in 2018. That is at least two times more than other American women in the sport.