Long - who has been nominated for Player of the Month for January - has scored nine times in his last 10 games but lasted just 18 minutes of the midweek draw at Cardiff before limping off.
The Republic of Ireland international picked up a hip injury and could be replaced by Noel Hunt if he doesn't make it.
New signing from Hereford, Mathieu Manset, is also in the running to start after he came off the bench to score at Cardiff.
Winger Jimmy Kebe returned from illness to play in Wales and should keep his place but central defender Alex Pearce is still out with a thigh injury.
Source: PA
Source: PA