The Australian centre-back will serve a one-match ban after he picked up two yellow cards in Saturday's 1-0 defeat at Colchester. Former Yeovil captain Paul Huntington will take his place in the starting line-up.
Westley is pleased to be able to call on Huntington for this clash.
He told the club's official website: "It is one of those fortunate things that we have lost a centre-half and we have gained a particularly motivated one for this occasion. It isn't a blessing in disguise, as we will miss Bailey, but we have good cover."
The Lilywhites will also be missing Stuart Beavon, Joel Byrom and Jack King, along with long-term absentees John Mousinho (hamstring) and Scott Laird (broken leg).
Keith Keane will maintain his place on the bench after recovering from injury.