Ever since , I think it 's been clearly going down this season . `` Also last year when I won Dubai , Rotterdam and Indian Wells , and the year before that , I did n't get tested in one of those three events that I won . Roger Federer wants more drug testing in tennis . Due to the debate over Viktor Troicki 's eligibility . Federer defeated Richard Gasquet at ATP World Tour Finals . Novak Djokovic into retirement after beating Juan Martin Del Potro .
Roger Federer wants more drug testing in tennis . Due to the debate over Viktor Troicki 's eligibility . Federer defeated Richard Gasquet at ATP World Tour Finals . Novak Djokovic into retirement after beating Juan Martin Del Potro .