Paris - The ITF's anti-doping manager says the tennis federation might copy measures pioneered by cycling to weed out drug cheats.
Stuart Miller told The Associated Press in a telephone interview that the ITF is also working hard to do more blood and out-of-competition drug tests on players.
Roger Federer and Andy Murray have called for more out-of-competition and blood testing after Lance Armstrong's fall. Murray said the Armstrong example was "pretty shocking."
Miller said the ITF is "looking very, very carefully" at introducing an athlete biological passport program in tennis.
Both cycling and track and field use such programs to monitor athletes' blood values, looking for telltale indications of doping.