Bethanie Mattek-Sands had to be wheeled off the court on a stretcher after injuring her knee in her second-round singles match against Sorana Cirstea at Wimbledon on Thursday.
The two women were tied at a set apiece when play was halted in the first game of the deciding set.
Mattek-Sands' knee appeared to buckle as she approached the net for a volley. She crumpled to the ground screaming in agony, and Cirstea hopped over the net and motioned for paramedics. Mattek-Sands remained on the ground for several minutes before she could be loaded onto the stretcher.
All England Club officials said Mattek-Sands had suffered an "acute knee injury" and was taken to a hospital, according to WTA Insider.
The 32-year-old American is the world's 99th-ranked singles player and its top-ranked doubles player, a distinction she has held since January. She's won five Grand Slam doubles titles, all in the past three seasons. Her last three major wins came with partner Lucie Safarova.
Safarova was in tears after arriving at the court to try to comfort Mattek-Sands.
