Robb suffered a hamstring injury against Dundee United at the weekend and has been rated "touch and go" for the clash at Ibrox.
Saints otherwise came through the Scottish Premier League defeat unscathed and the Buddies boss has no other injury concerns.
St Mirren (from): Gallacher, Mair, Barron, Potter, Robb, Carey, Thomson, Ross, Dorman, Dargo, Murray, Higdon, Mehmet, O'Donnell, Howard, Loy, Johnston, Faulds.







