TORONTO: Third seed Juan Martin del Potro was forced to withdraw prior to his opening match at the Toronto Masters on Wednesday due to a left wrist injury.
The Argentine, who looked to be in good form after reaching the final last week in Los Cabos, was replaced in the draw by Russian veteran Mikhail Youzhny.
Del Potro had a bye into the second round and was scheduled to face Dutchman Robin Haase.
The 29-year-old former US Open champion has struggled with a series of wrist injuries and was almost forced into an early retirement from the sport in 2016.