Novak Djokovic on Friday re-emphasised his strong support for longtime friend Maria Sharapova in her drug-test drama while adding that communication to player on the important subject of banned substances could be vastly improved.
"I think the communication from the governing bodies of tennis maybe should be a little bit better in terms of involvement of maybe ATP," the top seed said as he prepared to start at the Indian Wells Masters.
"I feel like sometimes ATP is stepping on the side because it's (anti-doping protocol) is a matter of ITF (the international federation) and WADA (anti-doping enforcers).
"There should be a little bit more of involvement maybe, people, players relations side, people engaged in this communication with players. You can say, 'if a player was informed once, it's not our fault that this player hasn't checked his email or thoroughly went through the changes.'
"But on the other side, we live a very busy life and there is a lot happening. I think at least what we can do is to have this kind of confirmation from the ATP side."
Five-time grand slam winner Sharapova awaits her fate after testing positive at the Australian Open for the recently-banned medicine meldonium which she has been taking 2006 on prescription from her doctor.
Anti-doping officials communicated through email to players before banning the substance from January 1, with Sharapova testing positive three weeks later.
The Russian - the highest earner in all of women's sport and the face of the WTA - said she somehow missed what officials said were the series of alerts sent during December.
Djokovic is caught between his friendship with Sharapova and his role as the ATP world number one.
He said that as a a friend "of course I do feel sorry about what's happening with her."
He added: "She has always been very responsible and aware towards herself, towards the sport, very disciplined, very kind of hard working and loving what she does.
"I really hope that she will find the best possible way. I thought she was very courageous and was very human to go out and take the responsibility and say what has happened. She did admit that she made a mistake with her team."
Djokovic said it was "completely normal" to expect that a player who has made a mistake "has to suffer certain kind of consequences."
He added that he has shied away in the past from physician-prescribed medicine due to fear of anti-doping consequences.
"You had to go through a procedure that is honestly very long, and it takes four, five days, at least to get the permission to do that if the tournament official doctor cannot really grant or guarantee for you to consume that substance.
"You are obliged to follow the procedure and to respect the process, and that's what you can do. That's why I think that maybe also this internal channels of communication between WADA and the athletes in sport can be better, can be improved, can be maybe more pro-active."