John Isner has been forced to pull out of the Cincinnati Open with a back injury.
The American was defeated in straight sets by Richard Gasquet in the semi-finals of the Rogers Cup on Saturday.
Despite coming through that match, the world number 11 has now ruled himself out of the warm-up tournament for the US Open. A lucky loser will be named as Isner's replacement.
Rafael Nadal, Jo-Wilfried Tsonga and Fernando Verdasco have also withdrawn from the tournament through injury.
Written by
Jack Prescott
Jack Prescott
