Christian Atsu has been forced to withdraw from Ghana's forthcoming 2014 World Cup qualifying fixture with Sudan.The midfielder suffered an ankle injury whiles playing for club, FC Porto in the Portuguese league over the weekend.Doctors have ruled him from Sunday's Group D game against the Nile Crocodiles at the Baba Yara Stadium, which means coach Kwesi Appiah's coach is down to 23 players from the original 24 named last week.Kwesi Appiah said: “We have spoken to FC Porto doctors and it is impossible for Atsu to recover in time for the game against Sudan. So officially, Atsu is out of the game.“We wish him speedy recovery and will continue to monitor his progress.”Black Stars squadGoalkeepers: Adam Kwarasey (Stromsgodset, Norway), Fatau Dauda (AshantiGold), Daniel Agyei (Liberty Professionals).Defenders: Harrison Afful (Esperance, Tunisia), Yaw Frimpong (TP Mazembe, DR Congo), Richard Kissi Boateng (TP Mazembe, DR Congo), Baba Abdul Rahman (Greuther Furth, Germany), John Boye (Rennes, France), Jonathan Mensah (Evian, France), Isaac Vorsah (Red Bull Salzburg, Austria), Awal Mohammed (Maritzburg United, South Africa)Midfielders: Emmanuel Frimpong (Fulham, England), Rabiu Mohammed (Evian, France), Emmanuel Agyemang Badu (Udinese, Italy), Kwadwo Asamoah (Juventus, Italy), Sulley Muntari (AC Milan, Italy), Wakaso Mubarak (Espanyol, Spain), Solomon Asante (TP Mazembe, DR Congo), Albert Adomah (Bristol City, England)Strikers: Asamoah Gyan (Al Ain, UAE), Abdul Majeed Waris (Spartak Moscow, Russia), David Accam (Helsingborg, Sweden ), Mahatma Otoo (Hearts of Oak)