Maria Sharapova has pulled out of next week's Canadian Open in Toronto with the arm injury that has cut short her latest comeback.
The five-time grand slam champion returned from two and a half months out with a thigh problem in Stanford this week but withdrew after only one match.
And the pain she suffered in her left forearm has now forced to sit out another tournament.
"I am so sorry to be missing Rogers Cup this year," Sharapova, who had been given a wildcard, said in a statement released by Tennis Canada.
"I am so appreciative to the tournament for the wildcard and my fans in Toronto for their support. I am disappointed that injury is keeping me from the tennis court once again, and I will work as hard as I can to return to the game I love as soon as possible."
Sharapova played three successive tournaments after returning from her doping ban in April before suffering the thigh injury in Rome that ruled her out of Wimbledon.
The Russian is waiting to find out whether she will be given a wildcard into the US Open having been refused one by organisers of the French Open before deciding against asking Wimbledon for direct entry.
Her ranking of 171 is high enough to earn a place in qualifying at Flushing Meadows.