Rangers' meeting with the current SPL leaders will kick off at 7.15pm and be broadcast live by the BBC.
The Scottish Football League today confirmed that the Gers will play on the Wednesday night with one other fixture also on that night.
Six other Third Round clashes will be completed 24 hours earlier.
TUESDAY 25th September 2012
Celtic v Raith Rovers 7.45 p.m.
St. Mirren v Hamilton Academical 7.45 p.m.
Queen of the South v Dundee United 7.45 p.m.
Heart of Midlothian v Livingston 7.45 p.m.
St. Johnstone v Queen’s Park 7.45 p.m.
Stenhousemuir v Inverness CT 7.45 p.m.
WEDNESDAY 26th September 2012
Rangers v Motherwell 7.15p.m. Live on BBC Scotland
Dunfermline Athletic v Aberdeen 7.45 p.m.