I'm afraid for Evans he's very much now on an upward climb to get in the team. When he was signed, he was probably 4th choice behind Clarke, Sharp and Lavery. This period now, where absences from the main strikers were supposed to provide that opportunity to get in the side, has unfortunately for Evans coincided with an injury that has limited his contribution.
He'll be off for his op, and by the time he returns will likely have Sharp, Clarke, Brooks, Donaldson, Lavery ahead of him, all of whom have done more with their appearances so far this season. I personally can't see him getting a look in – if he does we'll have had to have a particularly bad run of injuries to clear the path for him to come in.