American winger Gio Reyna missed Borussia Dortmund's exhibition against Athletic Bilbao because of a thigh injury sustained during warmups. Dortmund said the injury was slight and the 18-year-old was replaced by Goktan Gurpuz in the starting lineup for the 2-0 loss Satuday at St. Gallen, Switzerland. Dortmund opens the Bundesliga season on Aug. 14 at home against Eintracht Frankfurt. The U.S. starts World Cup qualifying on Sept. 2 at El Salvador. (For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)