Craig Levein was at St Johnstone's win over Kilmarnock six days ago and clearly liked what he saw.
The former Scotland boss only makes one enforced change as he names his first Saints side - midfielder Daniel Phillips replacing suspended forward Dara Costelloe.
Motherwell manager Stuart Kettlewell changes two from the side that lost 1-0 to Kilmarnock on Saturday.
Stephen O'Donnell comes in for Paul McGinn - who suffered a fractured cheekbone - at right-back, while striker Theo Bair is replaced with midfielder Callum Slattery.
Brodie Spencer and Calum Butcher both start despite suffering broken noses in that trip to Ayrshire.