Cisak had to leave the field in the closing stages of last weekend's 2-0 defeat to Swindon at Boundary Park having suffered a gash to the forehead that left him with concussion and requiring seven stitches.
The 23-year-old returned to light training on Thursday and will be assessed ahead of the trip to Huish Park, but the burden on boss Paul Dickov is eased as fellow keeper Dean Bouzanis is available once more having served a three-match ban.
Cliff Byrne was substituted after 16 minutes against the Robins due to a back injury but has returned to full training and expects to feature at the weekend.
Matt Derbyshire has returned to Nottingham Forest at the conclusion of his loan spell, meaning Robbie Simpson and Matt Smith are battling to partner Jose Baxter in attack.
- Sports & Recreation
- Dean Bouzanis