Naomi Osaka said she still does not feel like herself on court eight months into her comeback season following a maternity break, with the four-time Grand Slam champion puzzled at her lack of power and accuracy.

The 26-year-old was beaten by Ashlyn Krueger in the second round of qualifying for the Cincinnati Open, the latest setback in a patchy run of form heading into the final Grand Slam of the year at the U.S. Open, which runs from Aug. 26 to Sept. 8.

"My biggest issue currently isn't losses though, my biggest issue is that I don't feel like I'm in my body," Osaka wrote on Instagram on Tuesday.