Centre-half Carey has been sidelined with a heel injury but played 90 minutes for the reserves in midweek to prove his fitness.
The game will come too soon for Kalifa Cisse, who is back in training following a thigh problem.
Robins boss Keith Millen told the club's official website: "We still have to be careful with him. He had a number of injury problems at Reading last season and that's why it is important that we don't rush him.
"We'll be looking to give him some match practice next week and then see how far along he is."
Christian Ribeiro (back) could be named in the squad, but Nicky Maynard (knee), Danny Haynes (groin and thigh), Sam Vokes (hamstring), Lewin Nyatanga and James Wilson remain sidelined.