World No.1 Andy Murray has withdrawn from next week's Canadian Open in Montreal as he continues to recover from a hip injury, Tennis Canada has announced.
Murray has been in rehabilitation from the problem that ruined his Wimbledon campaign, but the tournament in Canada comes too soon.
"I am sad to be missing the tournament in Montreal because I have many great memories from my time in Canada," he said on the tournament's official website.
"I am doing everything I can to return as quickly as possible."
Murray was joined on the sidelines of the pre-US Open warm-up by Croatian world No.6 Marin Cilic. Former world No.1 and 2009 finalist Maria Sharapova also announced her withdrawal from the women's event on Thursday.
"We would have liked for Andy to be able to defend his title that he won here in 2015, but we wish him a very speedy recovery and to Marin Cilic as well following his great run at Wimbledon," said tournament director Eugene Lapierre.
The top two seeds at next week's event will be Rafael Nadal and Federer, with young guns Dominic Thiem of Austria and German Alexander Zverev rounding out the top four.