Ghana defender Isaac Vorsah will be out for the rest of the season in the Austrian Football Bundesliga after undergoing a successful surgery to correct an excruciating knee injury he sustained in last Tuesday’s Austrian Cup semi-final defeat to FC Traun.The Red Bull Salzburg defender ruptured his anterior cruciate ligament in his right knee and went under the knife on Friday and doctors have confirmed the lanky player will need six months to recover.Vorsah is likely to miss the remainder of the season and also the opening stages of the first half of next term of the Austrian Football Bundesliga.With this situation, the 25-year-old has been ruled out of Ghana’s double 2014 FIFA World Cup qualifiers against Sudan and Lesotho next month by doctors of the his club.Vorsah has been one of Black Stars dependable defenders and will be sorely missed for the busy month of June by the technical team, with this they will be looking for a replacement.FC Red Bull Salzburg have already qualified to play in the UEFA Champions league next season with just three matches to finish the season and are placed second on the radar with 70 points