WIMBLEDON, England — A day of attrition struck Wimbledon on Wednesday as the top two seeds in the men’s singles draw staggered out of the tournament because of injuries.

No. 1 Andy Murray, hobbling from a bothersome and prolonged hip injury, was upset by the American Sam Querrey in five uneven sets. Shortly afterward, No. 2 Novak Djokovic retired from his match with Tomas Berdych because of an elbow issue that has lingered for more than a year.

The tournament has been dogged by infirmities and retirements from the first round, when seven men quit their matches with injuries. Djokovic became the 10th man to drop out of a match.

Even the famed Wimbledon grass — brown, patchy and wilting — looks injured, too.

Djokovic and Murray slogged through their maladies until Wednesday afternoon. Both players said they would reassess their health and their schedules in the immediate future, which leaves some questions about their availability for the United States Open, which begins in late August.