Naomi Osaka's French Open hopes are in tatters after a shock first-up loss at the Italian Open on Wednesday.
In a day of carnage at the clay-court event, Osaka joined Serena Williams and Simona Halep in exiting the tournament.
The World No.2 suffered her latest stumble on clay - her least favourite surface - beaten 7-6 (7-2) 6-2 by Australian Open quarter-finalist Jessica Pegula.
Playing just her third tournament since winning the Australian Open in February, Osaka struggled to fight her way back into the match after losing the first-set tie-break to her 31st-ranked opponent.
The Japanese star also crashed out in the second round of the Madrid Open earlier this month.
"I'm not sure if I should be telling you this, but I'm just not that comfortable on (clay)," Osaka said before her loss in Rome.
"I'm not sure if it's because I need to play longer on it or if I just haven't grown up on it."
Osaka has seven career hard-court titles and won four grand slams (two each at the Australian Open and US Open), but has never managed to lift a clay-court trophy.
Her best result at the French Open is the third round.
"Mentally it's a bit harder because you have to structure the points differently," she said about playing on clay.
"There are bad bounces and stuff. I get quite frustrated. So, yeah, mentally I think it's a bit more taxing.
"But I think as soon as I get that sort of block out of my mind, then I'll be more open to the mistakes.
"Right now, I'm taking everything as a learning process, and I'm trying not to be so hard on myself."
Tennis world in disbelief over Naomi Osaka struggles
The tennis world continues to be baffled by her struggles on clay, with pundits and fans expressing their disbelief on Wednesday.
“Osaka. What a disaster," tweeted writer Jose Morgado.
"Unbelievable 2nd set from Naomi and not in a good way."
Fellow writer Dan Wolken wrote: "Osaka on clay is just a disaster right now.
"With this loss to Pegula, she’s just 1-2 on the Madrid/Rome swing.
"A good French Open result would really come out of nowhere at this point."
World No.1 Ash Barty will go into the French Open as the overwhelming favourite, with 2018 champion Halep tearing her calf on Wednesday.
The Romanian had to retire from her second-round match against Angelique Kerber while leading 6-1 3-3.
Halep massaged her left calf before hobbling to her bench, where she received treatment from a physio.
Unable to move, she decided to withdraw from the match and needed assistance to get off the court, causing doubt over whether she would be fit in time for the French Open, which begins on May 30.
She later wrote on Twitter that an ultrasound scan had revealed a tear in her left calf.
"I will get an MRI tomorrow to understand the injury in more detail, but at the moment we are unsure of recovery time," she said.
"I'm so disappointed to end my tournament in Rome like this but I will do everything I can to take care of the injury and be back as soon as possible."
Barty was given an early scare by Yaroslava Shvedova before winning 10 of the last 11 games to prevail 6-4 6-1 in 78 minutes.
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