Arsenal defender Kieran Tierney is facing up to three months out with a dislocated shoulder.
The Scotland international suffered the injury during the victory over West Ham on Monday.
The Gunners announced on Saturday that the summer signing from Celtic will have surgery next week and then began a rehabilitation process they said will last "around three months".
Former captain Granit Xhaka will miss Sunday's clash with Manchester City due to a concussion suffered in that West Ham game, while Rob Holding (knee) and Dani Ceballos (hamstring) are both out as well.
Nicolas Pepe, a scorer against West Ham, has overcome a bruised knee, though.
