It has become such a banal thing to admit Roger is doping, that I've seen references to it all over the Internet. Not only in the Comments sections of match reports, but also the subject matter has now been turned into an Animation Drama Series that is being produced by ATP bodies concerned about doping in Tennis.
This animation series concerns Roger attempting to use any kind of doping mechanism to defeat Rafa at the World Tour Finals and the Australian Open. Stan Wawrinka is also featured in the first episode of this Video series. http://www.youtube.com/watch?v=yFNQh2eQmxA