The four-time major-winner was knocked out in the fourth round by Slovak Dominika Cibulkova 3-6, 6-4, 6-1, the second upset in as many days after world number one Serena Williams was sent packing.
Third seed Sharapova took a medical timeout between the second and third sets and she said her left hip was troubling her after two tough matches earlier in the tournament.
"I have a bit of a strain the trainer told me in the hip area," said the Russian, who only came back from a shoulder injury at the Brisbane International this month.
"I mean, those aches and pains are expected when you spend a long time on the court. You just have to play through it."
She added: "I think it was just because I played a lot. This is only my second tournament back, so it was those types of things that are expected. You just have to find a way to block them out."
Maria Sharapova had endured two tough matches before meeting the Slovak, including a three-and-a-half hour epic in intense heat in the second round against Italy's Karin Knapp.
She admitted she had not been playing well, but said it was just good to be back in action after the shoulder injury sidelined her for months.
"I think it's a success (the tournament) in terms of that I'm back and that I'm healthy. That's quite important. Otherwise I wouldn't give myself a chance to play," she said.
"So on that note, yeah, I have to look at the positives and see where I have come from in four or five months. I haven't played a lot of tennis in those six months.
"So I certainly would have loved to play a little bit more before playing a Grand Slam, but this is the chance that I was given.
"I'm smart enough to be able to take it and acknowledge that I'm still pretty lucky to be in the draw and giving myself a chance to try to win it."