The 23-year-old has not performed a lot aggressive tennis in latest months after withdrawing from the French Open earlier this yr, citing psychological well being issues.
The event in Cincinnati was her first since bowing out within the third spherical on the Olympic Video games in Tokyo.
“I believed that, for me, I felt a bit hesitant, and usually I do not really feel that manner,” Osaka informed reporters after the 3-6 6-3 6-3 defeat.
“After all, I put myself on this place by selecting to not play that many tournaments, so, yeah, simply feeling extra snug with it, feeling extra assured in myself, as nicely, as a result of I really feel like there have been occasions the place I used to be doubting myself.
“I additionally thought that my efficiency in Tokyo was additionally lingering in my thoughts a bit as a result of I felt like I used to be overly aggressive there.”
It comes because the four-time grand slam champion continues easing herself again into the game after taking a break to guard her psychological well being.
After withdrawing from Roland Garros, she revealed she had been coping with anxiousness and bouts of melancholy and says she discovered it troublesome talking to the media throughout tournaments.
“I felt like I discovered rather a lot from this match at the moment, and if something to remove from this, I attempted my greatest all through your complete match, so I can sleep at night time,” she added.
Osaka will hope to rediscover her kind in time for the US Open on August 30, the place she is a two-time champion.