Coventry have doubts over David Bell and Richard Wood ahead of the clash with Scunthorpe.
Midfielder Bell, who came off the bench to net a superb winner against Crystal Palace last weekend, and central defender Wood sustained respective knee and hip injuries in training on Thursday and will be assessed over the next 24 hours.
Goalkeeper Keiren Westwood has not trained all week due to a slight ankle niggle but he is expected to do a full session on Friday and should be fine to face the Iron.
Midfielder Carl Baker also sat out over the first half of the week but returned to join the rest of the squad on Thursday.
Centre-back James McPake is okay to continue at the heart of defence having made his return from a back problem at Selhurst Park, while Leon Barnett is also available again after completing his one-match suspension.
Midfielder Martyn Woolford has been passed fit for Scunthorpe.
The former York man was substituted in the second half of the Iron's 1-1 draw with Ipswich on Tuesday night after taking a knock on his calf, but he will be in contention to face the Sky Blues.
Central defender Rob Jones trained on Thursday after missing the last two games with a broken nose but manager Nigel Adkins refused to comment on whether he will be available to face Chris Coleman's side.
If Jones is not deemed fit enough to return then Michael Raynes is expected to partner David Mirfin at the heart of the Scunthorpe defence once again.
Midfielder Michael O'Connor serves the second of a three-match ban for lashing out at Watford midfielder Tom Cleverley last weekend, while defender Andrew Wright (ankle) is still sidelined.
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