The world No. 2-ranked Russian withdrew Sunday saying she has yet to recover from the injury she sustained during a second-round loss to Michelle Larcher de Brito at this year's Wimbledon.
"I'm extremely disappointed that I am unable to play in Toronto next week as it's one of the best and most important tournaments of the year," said Sharapova in a statement. "I was looking forward to making a healthy return to the courts in front of my Canadian fans but unfortunately I'm just not recovered yet."
Sharapova tumbled several times during the Wimbledon match, complaining about court conditions, taking a medical timeout and later saying she thought she strained a hip muscle.
She subsequently withdrew from this week's Bank of the West Classic at Stanford University.
The Rogers Cup will take place Aug. 3-11 at Rexall Centre on York University campus in Toronto. The men's tournament takes place from Aug. 2-11 in Montreal.
Sharapova will still travel to Toronto to make a fan appearance on Thursday evening.