Serena Williams is ready to tackle the "biggest challenge of her career", according to coach Patrick Mouratoglou, as she prepares to return to the WTA Tour at the Indian Wells Masters.

The 36-year-old has not played on tour since winning the 2017 Australian Open – the 23rd grand slam singles title of her outstanding career.

Williams was two months pregnant when she won in Melbourne, and in September she gave birth to daughter Alexis Olympia.

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Her much-anticipated return to tennis almost happened in Australia in January, but Williams opted to withdraw from the year's first grand slam.

She featured in the United States' Fed Cup win over Netherlands, however, and Indian Wells is set to be her first tournament back on the WTA Tour.

Winning straight away it is not her priority, though, according to Mouratoglou, who says breaking Margaret Court's grand slam record is her main goal.

"Serena's target will be to win grand slams," he told WTAtennis.com.

"She knows that coming back might take some time, but her level of expectation is high as always. 

"There are three Grand Slams left this season. They will be her three main goals for 2018."

He added: "She is known for her comebacks. [But] I think we can say without doubt that this is her biggest challenge.

"The plan is to get back to her best level. She has been practicing hard for that, and competition is part of the process. She needs more than anything to compete and that is why she will plan to play Indian Wells and Miami.

"We do not know how much time she will need to get her best level back, and I think that we should give her the necessary time for that without having too much expectations at the start.

"I think she will be ready for Roland Garros. The competitions she will play until then will help her and every day she progresses on her fitness."