The centre-back has been troubled by a knee issue and has sought specialist help to overcome the problem.
Ross County have striker Ross Stewart back in their squad for the first time in 2020 following a hamstring injury.
Coll Donaldson remains out with facial fractures but the defender could return sooner than expected.
Motherwell provisional squad: Gillespie, Tait, Grimshaw, Hartley, Gallagher, Mugabi, Campbell, O'Hara, Polworth, Turnbull, Hylton, Long, Watt, Aarons, Seedorf, Ilic, Manzinga, MacIver, Maguire, Carson.
Ross County provisional squad: Baxter, Foster, Fraser, Fontaine, Kelly, Watson, Cowie, Spittal, Paton, Mullin, Tillson, McKay, Erwin, Vigurs, Spence, Stewart, Shaw, Laidlaw.