Five-time Grand Slam champion Maria Sharapova of Russia has offered a dim view of male players' support for gender equality in tennis, saying Briton Andy Murray has been one of the few "exceptions" championing the cause.

Women enjoy equal prize money at the Australian Open and the three other Grand Slams but are awarded less than men at other professional tournaments.

World number one Novak Djokovic caused outrage among women players when he said in 2016 that men should "maybe" earn more because their matches drew more spectators. He later apologized and backtracked on the comments.

Sharapova and three-time Grand Slam champion Murray once played mixed doubles together at the International Tennis Premier League in 2014 but have had few dealings since, particularly after the Russian was suspended for 15 months for taking banned drug meldonium in 2016.

Murray, the first top male player to take on a female coach in Amelie Mauresmo, questioned Sharapova's excuse that she was taking the drug for a heart condition and also criticized her racket sponsor Head for standing by her after she was caught doping.

When reminded about her doubles history with the Scot, Sharapova's memory was foggy.

"Did we play mixed doubles?" she said.

"Oh, right. I was, like, the only mixed doubles I played with was like (Max) Mirnyi and I think I was 16 or 17 maybe," she said of the former Belarusian professional.

"What do I remember? Clearly, it wasn't that memorable," she said with a smile.

"Because let me tell you, none of my doubles is memorable. It's like something we all should forget about. But I do have three titles. They actually mentioned it today in the introductions (on the court)."

"I was, like, 'OK, that's something we can skip. Like, let's not waste our time.'"