Former world number one Naomi Osaka says she does not "feel like I'm in my body" following her return to tennis after a maternity break.

Japan's Osaka returned to the WTA Tour in January after the birth of her first child, daughter Shai, in July 2023.

Since then, the four-time Grand Slam champion has struggled to rediscover her best form and been unable to advance past the quarter-finals at any tournament.

"My biggest issue currently isn't losses though, my biggest issue is that I don't feel like I'm in my body," Osaka, 26, 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."

Osaka was defeated by American Ashlyn Kreuger in the second round of qualifying for the Cincinnati Open on Monday.