Gouna forward Gamal Hamza was substituted against Zamalek because he picked up an injury, coach Ismail Youssef said after his side lost 1-0 to the Cairo giants on Friday. Hamza, who played against his former club for the first time since leaving them last summer, caused Zamalek all sorts of problems until being taken off eight minutes past the hour mark. His created several clear-cut opportunities but his teammates could not make use of his deft passes. He appeared disappointing when he was replaced with full-back Abdul-Moneim Ahmed. "Hamza played very well but I had to take him off because he sustained an injury," Youssef, a Zamalek star in the 1990s, said after the game. Substitute Sherif Ashraf, who replaced ineffective striker Ahmed Gaafar, gave Zamalek a precious late win after breaking the offside trap. The diminutive striker's goal could give him a new lease of life after coach Hossam Hassan demoted him to the bench. Gouna failed to ease their relegation worries as they remained third from bottom in the 20-team league table. "My players did their best today. If they maintain such good displays, we will have better results in the coming games," Youssef added. Youssef also criticized the referee for denying Gouna 'a clear penalty'. "We deserved to get a draw but the referee did not award us a clear penalty when Ahmed Omran was fouled in the area," he bemoaned.