Steroids are not widely used by tennis players

David Howman expresses his thoughts about anti-doping systems in certain sports organizations. While the director general of the WADA seems to be happy with jobs of certain sports organizations, he says that anti-doping programs in other leagues/teams are not suitable.
For example, the director general of the WADA praises the International Tennis Federation (ITF) for its anti-doping policy. David Howman says that anti-doping system is proper in tennis.
But when it comes to the National Basketball Association (NBA), it doesn’t want to adopt its anti-doping program to that of the WADA. It doesn’t agree to add several new drug tests in order to catch those that use steroids and/or other banned substances. That’s why David Howman confirms that the anti-doping policy of the NBA is not good enough to catch those who dope. He notes that the NBA should add more complicated new methods as well.
David Howman claims that drug tests conducted in tennis are of high quality. But there is a defect in tennis’ anti-doping system. A lot of tests take place during competitions. But few tests take place out-of-competition. That’s why ITF’s anti-doping system is also criticized.
Undoubtedly, nobody can confirm that anti-doping system of ITF is perfect. It has certain lacks too. But it is quite adequate.
So, you should not think that tennis is clean from doping totally. Certain tennis players probably use steroids and/or related medications. But it is not so tainted, as some other sports.
 Just one tennis player was suspended for administration of banned medications. However it seems to prove that tennis is clean, it is important to take in consideration that there are some methods to avoid positives. As you probably know, the celebrated cyclist Lance Armstrong administered steroids and other related medications and avoided detection much time. Couldn’t tennis players act the same way?