Bethanie Mattek-Sands suffered what appeared to be a serious right leg injury as she approached the net during today’s second-round Wimbledon match against Sorana Cirstea.

Right after her leg gave out, Mattek-Sands called for medical attention. She was down on the court for about 25 minutes under the care of staff before getting wheeled away on a stretcher. As a warning, the video’s a little intense:

If Mattek-Sands’s injury is as severe as it appears, it will end not just her singles run but her significant doubles run: Along with partner Lucie Safarova, Mattek-Sands is the No. 1 seed in women’s doubles at Wimbledon.