Stosur was never really in the hunt against American teenager qualifier Caty McNally, falling 6-1 6-4 in their Monday night clash.

The loss stretched her first round misery to five successive years.

The Queenslander will now concentrate on defending her Open doubles crown, won with Chinese partner Zhang Shuai, although this year she is playing with fellow Australian Ellen Perez.

Soon to be 36, Stosur said she hoped to return to Melbourne Park in 2021.

"I want to keep playing, no doubt," Stosur said.

"I guess my ranking is going to see where that allows me to keep playing.

"If I can win matches and do the things that I think I'm still capable of, then hopefully I'm still in the main draw of grand slams and having another shot."

While she admitted that in the past the pressure of playing in a home slam had been tough to handle, Stosur said she couldn't use that as an excuse.

"I don't use that as a reason or an excuse or anything like that.

"There's certainly been years in the past where I did struggle with that but at the moment I don't think it's that."

She said the conditions at Melbourne Park, as well as the balls, didn't really suit her game.

"I think the conditions I find really hard with these courts and balls," Stosur added.

"I just don't get the same reward off the court as what I do outside of Australia and I find that difficult every single time."

While grand slam singles titles may now be beyond her, Stosur said she is aiming to compete in a fifth Olympic Games in Tokyo, starting late July.

"If I can make it to a fifth Olympics, that would be quite incredible," she said.

"That would definitely be a highlight of the year down the track if I'm able to get myself to Tokyo."

Australian Associated Press