The four-goal striker has been struggling with a groin injury recently, but the Grecians have had a week off which has given him extra time to recover.
O'Flynn's return means Paul Tisdale has plenty of attacking options with Daniel Nardiello staking his claim with a late equaliser as a substitute to salvage a point against Oldham last time out.
The enforced break, due to Exeter being knocked out of the FA Cup and then seeing their midweek JPT clash postponed, has also given defender Richard Duffy a better chance of shaking off a slight hamstring injury.
The match is subject to a pitch inspection on Saturday morning.
Source: PA
Source: PA