The rescheduling of the tie means Ian Black, Darren Barr, Stephen Elliott and Gary Glen are now in contention to play, but Lee Wallace is doubtful after reporting into training on Monday ill.
Black, Barr, Elliott and Glen were doubtful due to illness for Sunday's match, but burst pipes at Tynecastle meant the tie was rescheduled, and now Wallace and Dawid Kucharski are unwell.
The extra two days may still not be enough for goalkeeper Marian Kello (back) to be included, while Rudi Skacel (calf) remains a doubt and Andrew Driver (thigh) and Suso Santana (knee) are out.
St Johnstone's Jamie Adams may have benefited from an extra 48 hours' rest, giving him further opportunity to recover following an ankle knock.
Long-term injured midfielder Kevin Moon has stepped up his training over the past couple of days following his recovery from a cruciate ligament injury.
Hearts (from): Kello, Barr, Bouzid, Zaliukas, Stevenson, Palazuelos, Templeton, Elliot, Elliott, Balogh, Kyle, Jonsson, Mrowiec, C Thomson, Skacel, Novikovas, Wallace, Obua, J Thomson, Kucharski.
St Johnstone (from): Enckelman, Grainger, Duberry, MacKay, Anderson, Maybury, Taylor, Davidson, Morris, Craig, Millar, MacDonald, Adams, Samuel, Parkin, Smith, Reynolds, May, Caddis.