Elina Svitolina's place at Wimbledon is in doubt after the world number five was troubled by a foot injury during her defeat to Camila Giorgi at the Aegon Classic on Thursday.
Svitolina is expected to do well at the All England Club next month but she may not be in attendance following her 6-4 4-6 6-2 loss in Birmingham.
The Ukrainian lost her serve seven times in the second-round match, three coming in the decider as Giorgi claimed her second win over a top-10 player this season.
"I'm disappointed I'm out of the tournament, but not disappointed about my performance because I couldn't really show even like 50 per cent of what I can do," said Svitolina.
"I was really looking forward to this year at Wimbledon. But today the court was slippery and it's so bad for my foot.
"I will do my best. But for the moment it's very uncomfortable, and there is a question, I think, about it, because the season is still long and there is lots of big tournaments as well where I will feel more comfortable and confident on the hard court."
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Garbine Muguruza had no such problems as she thrashed Alison Riske 6-1 6-4, the former Wimbledon finalist hitting 26 winners in the match and only losing her serve once.
Muguruza racked up six successive games on her way to victory and will now face Coco Vandeweghe in the last eight.
Vandeweghe caused an upset as home favourite Johanna Konta was comprehensively brushed aside in just 66 minutes.
Konta struggled for rhythm throughout and her American opponent was in no mood to let her find it, Vandeweghe storming to a 5-0 lead before serving out for the set.
Things were a little better for Konta at the start of the second but Vandeweghe applied pressure in the seventh game and never looked back, the world number 30 reeling off three games in succession to seal victory.
Fifth seed Kristina Mladenovic completes the quarter-final line up after a 6-4 7-6 (7-3) win over Shuai Zhang, the Frenchwoman setting up a meeting with two-time Wimbledon champion Petra Kvitova.