Ross County have both Liam Fontaine and Brian Graham suspended for their Dingwall clash with Hearts.
Ross Draper is free from a ban but struggling with a knee injury so he is also unlikely to feature in the Ladbrokes Premiership fixture.
Ross Stewart (hamstring) and Tom Grivosti (foot) are also on the casualty list but Don Cowie (knee) could return after making a 60-minute run-out for the Staggies reserve side this week.
Michael Smith and Aaron Hickey are expected to miss out for Hearts after going off injured against Airdrie on Saturday.
Sean Clare is suspended following his recent red card against Aberdeen while Peter Haring remains sidelined with pelvic trouble and both Jamie Brandon and Callumn Morrison are still out.
Wide player Donis Avdijaj could make his debut after joining from Trabzonspor.
Ross County provisional squad: Baxter, Foster, Fraser, Kelly, Donaldson, Morris, Watson, Cowie, Spittal, Paton, Chalmers, Mullin, Tillson, Reid, McKay, Erwin, Henderson, Vigurs, Gardyne, Laidlaw.
Hearts provisional squad: Pereira, White, Halkett, Dikamona, Souttar, Bozanic, MacLean, Meshino, Damour, Ikpeazu, Naismith, Walker, Henderson, Irving, Moore, Avdijaj, Garuccio, Zlamal.
