I think the save was a very good parry in the first half from a narrow angle which went out for a corner.
Serbia's chances were a one-on-one (can't blame the keeper), an excellent lob (keeper suspect) and the forward getting above two defenders 8 yards out (shouldn't have been let get as good a header away from there). Luxembourg haven't anyone of the quality of Tadic and Mitrovic; I wouldn't be too worried about putting Travers in for that.