Stand-in skipper Webster missed his side's 4-2 defeat to Ross County with a thigh strain but is back in contention for this weekend's match at Rugby Park in the Clydesdale Bank Premier League, while Barr has overcome a lingering ankle complaint.
Locke, however, will have to monitor Gordon Smith after he was injured in an Under-20s match with Motherwell in midweek.
Long-term absentees including captain Marius Zaliukas and Danny Grainger remain unavailable.
- Sports & Recreation
- Clydesdale Bank Premier League