Andy Murray withdrew from the Rogers Cup because of a knee injury Thursday, the latest top player to pull out of the rain-delayed tournament.
The Olympic gold medalist hurt his left knee Wednesday night during the opening match against Flavio Cipolla. Murray was scheduled to face Canadian Milos Raonic in the third round Thursday night.
Those matches were, in fact, rained out as heavy weather hit the Toronto area.
"Normally when I move on to hard courts, I have 10 days or so practicing and you feel things like this, but you can work around it by doing the right training and what not," Murray said. "I don't want to go full out and possibly do any more damage. That was why I decided not to play."
Murray, ranked fourth in the world, said he's unsure whether he can play in Cincinnati next week or what his status is for the U.S. Open.
"Over the next few days we'll come up with a plan and strategy to either get myself ready for Cincinnati, or if not, then plan for the best way to prepare for the U.S. Open," Murray said. "But today I won't think about any strategies or whatever. It'll just be about what's the next move and where do we go from here."
Roger Federer and Rafael Nadal withdrew before the tournament began.
Raonic reached the quarterfinals for the first time in a Masters tournament.
"Obviously, it's something that I was really looking forward to," Raonic about playing Murray. "It's an unpleasant thing, but at the same time it's a good thing — it's my first quarterfinal in a Masters and to be at home is pretty special. I guess there's a give and take with it. I'm playing pretty well, I'm healthy, so it's a good opportunity and I'm going to make the most of it come tomorrow."
Murray's absence leaves the tournament shy on star power and without three of the world's top four players in men's tennis. World No. 3 Rafael Nadal pulled out just prior to the tournament because of injury and announced Thursday he will also miss the ATP Tour's next stop in Cincinnati.
Federer withdrew from the Rogers Cup a day after Nadal, citing the schedule crunch with the Summer Games.
Top-seed and world No. 2 Novak Djokovic was set to play American Sam Querrey on Thursday but that match was delayed by a steady drizzle that wreaked havoc on the day's schedule.
All singles matches were postponed while some doubles matches were shifted to a nearby covered court.
Fans were left with little more to do than visit covered food courts and souvenir shops while they waited for conditions to improve. A helpful Djokovic tried to lighten the mood by sweeping water off the stadium court and even hit a few balls while holding an umbrella.
Toronto's Daniel Nestor and partner Max Mirnyi of Belarus got their opening match in with a 6-4, 6-3 victory over Italy's Fabio Fognini and Juan Monaco of Argentina.
"It wasn't the prettiest match," said Nestor. "It was dark in there and no one was on their game. We just happened to win one or two of the bigger points, more by luck than by playing well."
The win officially qualifies Nestor for the ATP World Tour Finals in London. The top-ranked duo are the first team this year to qualify for the November championship held annually at O2 Arena. It will be Nestor's 14th appearance at the year-end tournament as he look to defend his title.
"For whatever reason I've had success there the last few years and I think we're going to be, hopefully, one of the top two teams," said Nestor. "Any time you're in a dog fight for No. 1 this late in the season you're know you've done something well."
For Murray, who is ranked fourth in the world, he's unsure whether he can play in Cincinnati or what his status is for the upcoming U.S. Open.
"Over the next few days we'll come up with a plan and strategy to either get myself ready for Cincinnati, or if not, then plan for the best way to prepare for the U.S. Open," said Murray. "But today I won't think about any strategies or whatever. It'll just be about what's the next move and where do we go from here."
Raonic, meanwhile, awaits the winner between John Isner of the U.S. and Germany's Phillipp Kohlschreiber, though that meeting too was delayed by rain.
If Isner advances it would mean a matchup between two of the hardest serves on the Tour.
"I look forward to whoever it is against," said Raonic. "My job is take care of my serve and try to make the most of my return games. I feel like I'm returning a lot better. I feel like I'm improving on that aspect of my game. And I think my serve is there, so I will try to make the most of it the best I can against whoever it may be against."
Raonic's only win over a top-eight player this year came against Murray in Barcelona in April. He was scheduled to meet Murray at the Sony Ericsson Open in March, but pulled out because of a sprained right ankle.
Murray joked that this was payback for pulling out against him in Miami.
"We repaid him the favour today," he said. "I think it would have been a fun match. I hope he has a good tournament. Be great for him to go deep in this tournament for the first time."