Nadal pulls out of US Open tuneup in Montreal

Rafael Nadal has withdrawn from next week’s US Open tuneup event in Montreal due to the same abdominal strain that forced him to miss his Wimbledon semifinal last month, he said Friday.

Nadal, who is No. 3 in the world rankings, had his quest for a calendar Grand Slam end when he pulled out of his anticipated Wimbledon showdown vs. Australia’s…