Murray Davidson is out of St Johnstone’s home Ladbrokes Premiership game against Kilmarnock.
The 31-year-old has sustained a fracture to his left arm in training which will rule him out for a minimum of six weeks.
Matty Kennedy has played his last game for Saints after moving to Aberdeen.
Rory McKenzie returns to the Kilmarnock squad.
The Rugby Park attacker has recovered from a hamstring strain and is back in training.
Striker Innes Cameron remains out of contention with a knee problem.
St Johnstone provisional squad: Clark, Duffy, Ralston, Booth, Tanser, Vihmann, Gordon, Kerr, Holt, Swanson, Craig, McCann, Wright, O’Halloran, Kane, May, Wotherspoon, Hendry, Parish.
Kilmarnock provisional squad: Branescu, O’Donnell, Hamalainen, Johnson, Bruce, Del Fabro, Dicker, Frizzell, Wilson, El Makrini, Brophy, McKenzie, Bunn, Burke, St Clair, Kiltie, Kabamba, Hendrie, Koprivec.