MELBOURNE, Australia — Canada's Vasek Pospisil has dropped out of the Australian Open because of a back injury.

The native of Vernon, B.C., who is ranked 70th in the world, hasn't played since October.

"Very sad to have to withdraw from the @AustralianOpen today," the 28-year-old Pospisil tweeted. "Unfortunately I have yet to fully recover from the back injury I sustained in October. Hope to be back soon."

Milos Raonic of Thornhill, Ont., and Denis Shapovalov of Richmond Hill, Ont., are the two remaining Canadians in the main men's singles draw for the Australian Open.

The first Grand Slam of the season begins Jan. 14.