But manager Kevin Blackwell will be boosted by the return from suspension of forward Darius Henderson and could recall Henri Camara to his starting line-up, with Mark Yeates or Stephen Quinn stepping in for Williamson.
Blackwell has no other new injury or suspension problems as his side look to get their play-off push back on track after back-to-back defeats, but long-term absentees Gary Naysmith, Ryan France (both knee) and Derek Geary (ankle) remain sidelined.
Source: Team Talk
