Naomi Osaka said she still does not feel like herself eight months into her comeback season following her latest defeat at the Cincinnati Open. (More Tennis News)
Osaka was beaten in three sets by Ashlyn Krueger in the second round of qualifying for the event ahead of the final grand slam of the year at the US Open.
The former world number one also lost in her first match of the Paris Olympics to Angelique Kerber and was beaten in the last 32 of the Canadian Open last week.
Osaka was left puzzled by her lack of accuracy and power in her most recent loss, explaining her current form is having an affect on her mentally.
"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.
"It's a strange feeling, missing balls I shouldn't miss, hitting balls softer than I remember I used to.
"I try to tell myself, 'It's fine you're doing great. Just get through this one and keep pushing', mentally it's really draining through.
"Internally, I hear myself screaming, 'What the hell is happening?!?!'"
Osaka returned to action in January after a 15-month break during which she gave birth to her daughter.
The Japanese is now ranked 90th in the WTA rankings, with her best finishes coming in Doha and 's-Hertogenbosch where she reached the quarter-finals in both.
"I've played a handful of matches this year that I felt like I was myself and I know this moment is probably just a small phase from all the new transitions (clay, grass, clay, hard), however the only feeling I could liken how I feel right now to is being post-partum," Osaka said.
"That scares me because I've been playing tennis since I was three, the racket should feel like an extension of my hand."
Osaka's next event will be at Flushing Meadows, a stadium where she triumphed in 2018 and 2020, but added she did not understand why everything about her game felt brand new again.
"This should be as simple as breathing to me, but it's not," she added. "I genuinely did not give myself grace for that fact until just now."