Aberdeen centre-backs Scott McKenna and Ash Taylor both miss out with hamstring injuries for the visit of Ross County.
McKenna was ruled out for three or four weeks while Taylor suffered a setback in his recovery.
Midfielder Dean Campbell is again a doubt for the Ladbrokes Premiership contest with a knock.
Former Dons full-back Richard Foster could feature for County after returning to Dingwall from St Johnstone.
The visitors have a lengthy injury list which includes Lee Erwin, who faces six weeks out after going over on his ankle.
Ross Draper (knee), Brian Graham (hamstring, Don Cowie and Lewis Spence (both knee) remain out while Liam Fontaine, Michael Gardyne and Nathan Baxter are doubts.
Provisional Aberdeen squad: Lewis, Logan, Leigh, Vyner, Considine, Devlin, Ojo, Gallagher, McGinn, Hedges, Ferguson, Bryson, Wright, Cosgrove, McLennan, Main, Wilson, Anderson, Campbell, Cerny.
Provisional Ross County squad: Laidlaw, Ruddy, Foster, Fraser, Fontaine, Grivosti, Watson, Morris, Kelly, Vigurs, Spittal, Paton, Chalmers, Mullin, Gardyne, Stewart, Armstrong, Reid, McKay.
