Cuthbert hurt his hamstring during last weekend's defeat against Stevenage and boss Nathan Jones has confirmed the Scotsman will be out for "a few weeks".
Dan Potts will be assessed after he was carried off with a head injury in the draw against Carlisle on Tuesday.
Fellow full-back James Justin could deputise for Potts if he misses out.
Exeter boss Paul Tisdale has no new worries for the trip to their play-off rivals.
Reuben Reid scored twice in Tuesday's 3-0 win against Cheltenham and was substituted just before the hour to preserve him for the Hatters clash.
It remains to be seen if his replacement, Ollie Watkins, can force his way back into the starting line-up.
Goalkeeper Christy Pym sat out a fourth game with a groin problem in midweek but Bobby Olejnik has impressed since coming in. Lee Holmes, Robbie Simpson and Tom McCready are long-term absentees.