Former top-10 player Marin Cilic has been suspended nine months for a doping violation.
The International Tennis Federation says Czech player Barbora Zahlavova Strycova has been banned six months for doping.
Bulgarian tennis player Dimitar Kutrovsky has been banned for two years after testing positive for a banned stimulant.
American tennis player Robert Kendrick had his doping ban reduced to eight months from one year by the Court of Arbitration for Sport on Monday.
The Court of Arbitration for Sport says it will rule on tennis player Robert Kendrick's doping ban appeal before the U.S. Open.
Former top 100 player Robert Kendrick of the United States was suspended for a year by the International Tennis Federation on Friday after testing positive for a banned stimulant at the French Open.
Brazilian tennis player Marcelo Melo was banned for two months Monday for a doping violation.
Italian tennis player Giulia Casoni tested positive for a banned substance and has been suspended pending an inquiry into the case.
Argentina's Mariano Puerta tested positive for a banned stimulant following his loss to Spain's Rafael Nadal in the French Open final in June.
At least one player tested positive for a banned stimulant at this year's French Open, the French sports daily L'Equipe reported on Friday.
The World Anti-Doping Agency has no plans to intervene in U.S. Open champion Svetlana Kuznetsova's positive drug test.
Svetlana Kuznetsova has tested positive for a banned drug, Belgian sports minister Claude Eerdekens said Monday. The U.S. Open champion says she is not a drug cheat and is angry at the Belgian authorities.
Two unidentified players failed drug tests at the French Open, France's Council to Prevent and Fight Doping reported Monday.