Birmingham - World number five Elina Svitolina said she could miss Wimbledon with a heel injury, after slumping to a second-round defeat by qualifier Camila Giorgi in Birmingham on Thursday.
The 22-year-old Ukrainian was clearly struggling as she slid to a 6-4, 4-6, 6-2 loss to a player ranked outside the top 100 at the Wimbledon warm-up event.
Afterwards she suggested she would consider pulling out of the third Grand Slam tournament of the year, which starts on July 3.
"There is a question about it," she admitted. "I will talk with my physios. The season is very long and I must look at the bigger picture.
"The heel feels painful and is very sensitive. I am disappointed I am out of the tournament but I am not disappointed with my performance, because I could not show even 50 percent.
"Also the court was slippery which is bad for the foot."
The lush grass in the English midlands is utterly different to the clay on which Svitolina won the Italian Open and reached the French Open quarter-finals, where she missed a match point against eventual runner-up Simona Halep.
Combined with a sudden change from Wednesday's fierce heat to drizzle and damp, it became hard for the stricken Svitolina to cope.
Giorgi adapted to the slick surface very well, hitting some raging forehand drives, finding some good angles, and occasionally coming to the net effectively.
The Italian played close to the standard that two years ago took her to 30 in the world.
With Dominika Cibulkova having already lost in the first round, the two leading seeds have both departed early, following belated withdrawals from four other top-10 players.
Giorgi will have a quarter-final against another surprise survivor, Ashleigh Barty, a 21-year-old Australian making her first appearance in the main draw.
Later Thursday, fourth seed Johanna Konta, the highest-ranked British player for more than 20 years, was overwhelmed 6-1, 6-3 by Coco Vandeweghe, the tall American who reached the top 20 for the first time this year, and whose powerful game is ideally suited to grass.
Konta lost the final of the Nottingham Open four days previously, and showed little sign of being able to contain Vandeweghs's impressively big game.
"The match showed two ends of the spectrum. She (Vandeweghe) played very well and was hitting a big ball," said Konta.
"For me, I didn't find my footing and once you go down as I did in the first set it's very difficult to get back in the match. I think I did a reasonable job of playing as well as I could after that but it was nowhere near enough."
Fortunately for the depleted tournament, Garbine Muguruza survived.
The former French Open champion and Wimbledon finalist hit solidly and forcefully from the baseline while winning 6-1, 6-4 against Alison Riske, the American who has twice been a semi-finalist in Birmingham.
Quizzed about her chances of further progress and whether she was well set for a long run at Wimbledon, Muguruza answered: "A lot of people are thinking because the three big names or whatever are not playing now, 'oh, that's my opportunity' or 'I should reach the final'.
"In fact I see the winners at the moment, and it's the players that weren't the favourites. So I think everything is very equal right now."
The tournament's other former Grand Slam champion, Petra Kvitova, twice a Wimbledon winner, learned that her quarter-final opponent will be Kristina Mladenovic, who ended Muguruza's French Open title defence a fortnight ago.
The world number 12 from France earned this intriguing match-up with a 6-4 7-6 (7/3) win over Zhang Shuai of China.
Results from the WTA tournament in Birmingham on Thursday (x denotes seeding):
Kristina Mladenovic (FRA x5) bt Zhang Shuai (CHN) 6-4, 7-6 (7/3)
Garbine Muguruza (ESP x6) bt Alison Riske (USA) 6-1, 6-4
Coco Vandeweghe (USA) bt Johanna Konta (GBR x4) 6-1, 6-3
Camila Giorgi (ITA) bt Elina Svitolina (UKR x2) 6-4, 4-6, 6-2