Karim Darwish has withdrawn from the Davenport North American Open.
The Egyptian number five seed has a leg injury, believed to be a calf strain.
His exit gives reigning champion James Willstrop, the PSA president, a walkover into the semi-finals.
Darwish recently pulled out of the Motor City Open final in Detroit against compatriot Amr Shabana after suffering a calf muscle injury.