Describing Rusedski's prospects as "a close call," Dr John Gaynor, the physician at the Queen's Club tournament, said, "I would think it's not as much as 50-50, to be fair."
Rusedski, the world No 4 and British No 1, does not have to make a final decision until 15 minutes before his first match is called. He is likely to request a Tuesday start.
The injury occurred with the score at 2-2, 30-30, in the first set of the second-seeded Rusedski's third round match against Laurence Tieleman, an Italian qualifier. During Tieleman's service game, the left-handed Rusedski moved towards the net from the baseline to play a backhand volley, screaming as he lost his footing and slid into the tramlines, the left ankle appearing to turn under his body as he fell.
"I felt something go pop," Rusedski told his coach, Tony Pickard, after being helped off the court by Doug Spreen, the ATP Tour trainer, and Jolyon Armstrong, the media director. He was taken to the Cromwell Hospital for X-rays and an MRI scan.
Rusedski was defeated by Cedric Pioline, of France, in the Wimbledon quarter-finals last year. He went on to reach the final at the United States Open in September, losing to the Australian Pat Rafter. His progress in New York helped the Canadian-born Rusedski to became the first Briton to break into the top 10 in the ATP world rankings. He rose to No 4 and ended the year with a clutch of sportsman of the year awards.
Rusedski's was among the favourites for the Wimbledon men's singles title. Corals had quoted him 9-1 second favourite behind Pete Sampras, the four- times champion.
Although rain and wind had affected the first four days play at Queen's Club, yesterday was sunny and tranquil by comparison. "I wouldn't have been as surprised if it had happened the night before," Pickard said, "but today was a beautiful day and there was nothing wrong with the courts."
At the time, Tim Henman, the British No 2, was in the process of defeating Goran Ivanisevic on the adjacent Centre Court, 6-1, 6-7, 6-4. Henman, the No 7 seed, was beaten by the 235th-ranked Tieleman in the quarter- finals last night, 2-6, 7-6, 6-4, as the tournament's organisers struggled to keep the event on its right schedule.
"I'm very sorry to hear about Greg," Henman said. "I hope he is able to play at Wimbledon. I wasn't aware of what was going on while I was on the court this afternoon."
Although Rusedski will not be able to defend his Nottingham Open title next week, Pickard remains optimistic about Wimbledon. His parting shot was, "Let's all keep our fingers crossed."
Henman on a high, page 23