Premier Sports are showing two matches live - first up is the Group C meeting of St Johnstone and Dundee at McDiarmid Park this evening then tomorrow it's St Mirren v Morton in Group G.
Hearts just need a point to be sure of a place in the last 16 on the weekend of November 28/29 when they face East Fife at Bayview in Group A tonight.
Dundee will move to the top of Group B if they can beat League 1 leaders Cove Rangers at Dens Park while Group D leaders Elgin City host Ross County.
Falkirk will move level with Dunfermline Athletic at the top of Group E if they win at Dumbarton. Group F leaders Ayr United don't play this midweek while Livingston, who top Group H, are away to Stenhousemuir.