The 12-goal frontman is struggling with hip/thigh problems and will be assessed ahead of the clash as the Sky Blues look to bounce back from Saturday's surprise 5-1 mauling at the hands of lowly Tranmere.
Midfielder Adam Barton definitely misses out having been forced off in the second half at the weekend with a knee injury, while defender Jordan Willis (knee) also remains sidelined.
But City are boosted by the return of midfielder Conor Thomas after a one-match suspension.
The Millers have a potential shortage of strikers ahead of the trip.
Alex Revell was taken off during Saturday's disappointing 0-0 draw with Carlisle with a knock and will have a fitness test while on-loan Tom Eaves has returned to parent-club Bolton.
That could mean Nouha Dicko gets a start in attack alongside Matt Tubbs, but there may be no recognised strikers on the bench.
Mark Bradley, who was originally expected to be fit for this clash, is still struggling with a groin problem and will play no part, while David Worrall (virus) is still not ready.