Marseille winger Andre Ayew, 22, was due to undergo an operation on an injured left shoulder today and will be sidelined for three months as a result, his club announced on their website.Ayew has dislocated his left shoulder on several occasions this season and, after previously putting off surgery, he has finally agreed to go under the knife in Lyon.Ayew, who plays alongside his younger brother Jordan at the Stade Velodrome, has scored eight league goals in a disappointing campaign for OM.