Michael Duberry is out of the game.
The 34-year-old defender was forced off by a groin injury in the first half of Saints' 4-0 defeat by Rangers at Ibrox on Sunday and manager Derek McInnes is bracing himself for scans on Tuesday showing that the former Chelsea player could be out for up to six weeks.
Kevin Moon (groin), Chris Millar (hamstring) and Jamie Adams (ankle) are out and Sam Parkin (broken ankle) will not figure for the remainder of the season.
Aberdeen's Chris Maguire begins a two-match ban.
Zander Diamond is a doubt with an ankle injury but manager Craig Brown expects David McNamee to shake off a hamstring strain.
Peter Pawlett (knee) remains on the sidelines alongside long-term absentees Yoann Folly, Darren Mackie and Fraser Fyvie.
St Johnstone (from): Enckelman, Grainger, Maybury, MacKay, Anderson, Taylor, Invincibile, Morris, Craig, Davidson, Samuel, May, Novikovas, MacDonald, Gartland, Caddis, Smith, Reynolds.
Aberdeen (from): Langfield, McNamee, Smith, Considine, Diamond, Vujadinovic, Milsom, Jack, Young, Aluko, Hartley, Vernon, Blackman, McArdle, Paton, Magennis, Anderson, Howard.