It's OK, they won't find anything in Football or Tennis, because they don't look. Look up "Operation Puerto" - loads of athletes (mainly Spanish) were implicated, but they only went after the cyclists, Nadal, Barcelona, Real Madrid, etc were allowed to carry on juiced up with no investigation.
Cycling gets a bad name because people get caught for doping. Tennis/football/etc are proclaimed as "clean", because few get caught, but then you won't catch people if you don't attempt to catch people. At the European Championships in 2008, they didn't bother testing for a number of substances, citing that it was "too expensive", which is ironic considering football is probably the richest sport.