Novak Djokovic that Maria Sharapova must face the consequences of her failed drug test at the Australian Open on 11 March. On 8 March, the Russian tennis star announced she had failed a drug test because she had been taking the medication meldonium, under her doctor's supervision.

"Certainly if there was a mistake and she was thought to be positive on doping for a certain substance then there should be a certain kind of consequences for that," Djokovic said. "The player that has made this mistake has to suffer certain consequences and she's aware of that."

Djokovic added that he and Sharapova have been friends for a long time, and he was surprised when Sharapova made the announcement that she had failed a drug test.

"I thought she was very courageous and it was very human and brave of her to go out and take the responsibility and say what has happened and she did admit that she made a mistake," the 28-year-old Serb said.

Djokovic, a four-time winner of the Indian Wells tournament, also said he communicates regularly with his team and is well aware of any changes to the banned substances list.

"If there is any significant changes that I need to be aware of, I am aware of, they do let me know so we communicate of course on a daily basis," Djokovic said before adding that he doesn't believe in using performance-enhancing drugs. "I wouldn't say that there is a magic potion or an elixir that can make you feel better."