The on-loan Watford man has been called up to Northern Ireland's Under-21s squad and will miss both this fixture and his side's trip to Burton on Saturday.
This game looks to have come too soon for midfielder Marc Laird, who has missed the last seven matches with a hamstring injury.
Midfielder Conor Clifford is expected to keep his place in the side after scoring his first goal for the club in the 2-0 victory over Oxford.
- Sports & Recreation
- Marc Laird