Kyle Munro and Ross Callachan dropped out of the squad last weekend after the club reported several positive Covid-19 cases, while Lee Hodson is also back after his flatmate, St Mirren goalkeeper Jak Alnwick, tested positive.
Skipper Brian Easton could return some time in October following ankle surgery.
Defender Mark Connolly is back in contention for Dundee United after an ankle injury.
Liam Smith is still a doubt for the Tayside club.
The full-back has not played since picking up a heavy knock against Motherwell on August 8.