Teenage defender Gibson, who has been borrowed from Middlesbrough, has been struggling with a mysterious injury for a while and did not feature in the 2-2 draw against Portsmouth on Saturday.
A specialist has subsequently discovered Gibson's injury is an abductor problem and the centre-back faces up to two months on the sidelines.
While Moore concedes a few of his other players are carrying knocks, the Rovers squad is likely to be similar to the one which drew with Pompey.
There are a host of players on the sidelines, though, with captain James Wallace (knee), striker Jean-Louis Akpa Akpro (broken metatarsal) and winger Abdulai Bell-Baggie (knee) all long-term injury victims.
- Sports & Recreation