American Andy Roddick withdrew from the Toronto Masters tennis tournament on Tuesday due to illness.
The former world No. 1 lost in the third round in Washington a week ago, saying he was feeling unwell.
The American's summer started poorly with an early Wimbledon loss and a semifinal defeat in Atlanta by Mardy Fish.
Chile's Fernando Gonzalez, who has not played since the French Open due to a left calf injury, also pulled out.