Cardiff City full back Kevin McNaughton will be out of action for up to two weeks with a pulled hamstring.
Naughts, who hopes to be in contention to face Preston on December 5, went off during the first half of Saturday's 1-0 defeat at Barnsley - his first league start since rupturing ankle ligaments in the July friendly against Celtic. City's medical staff will also be investigating a back injury which they suspect could be causing hamstring trouble.
Better injury news for City is that Jay Bothroyd (knee), Anthony Gerrard (calf strain) and Adam Matthews (groin) are all expected to be fit for Sunday's home clash with Ipswich Town.
Another bonus is that forward Kelvin Etuhu, on loan from Manchester City, is back at Cardiff after suffering an ankle injury in the match with Newcastle on September 13. He is expected to take some part in training and will also undergo fitness tests to determine a date for his return to action.