Bethanie Mattek-Sands is having more scans on a serious knee injury she picked up during her second-round Wimbledon singles match on Thursday.
The American screamed in agony after slipping during the third set against Romania's Sorana Cirstea on court 17.
The Women's Tennis Association (WTA) said more will be known following Friday's tests.
"Bethanie of course thanks everyone for their kind wishes and messages of support," the WTA statement added.
Mattek-Sands was treated by paramedics on the court before being carried off on a stretcher and taken straight to hospital.
More to follow.