Elina Svitolina may be forced to withdraw from Wimbledon after picking up a foot problem.
The world No. 5 was knocked out of the Aegon Classic in Birmingham by Camila Giorgi on Thursday.
Svitolina has been one of the form players of the season but has only ever won two matches at Wimbledon and does not want to jeopardise her chances of success on hard courts.
The Ukrainian said: "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.
"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."
Svitolina started the Aegon Classic as the highest-ranked player following the withdrawal of world No. 1 Angelique Kerber, but the second seed was out-hit by Italian qualifier Giorgi, who triumphed 6-4 4-6 6-2.
Giorgi, ranked 102, moves through to a quarterfinal clash with Australia's Ashleigh Barty.
There was disappointment for British No. 1 Johanna Konta, who crashed out after a straight-sets defeat to American Coco Vandeweghe.
World No. 7 Konta won only 11 points as she lost the first set inside 24 minutes and although she improved in the second set fell to a 6-1, 6-3 reverse in 64 minutes.