The eight-goal striker will begin a four-match ban after being shown his second red card of the season during Tuesday night's 2-0 defeat against MK Dons for a dangerous tackle on midfielder Stephen Gleeson.
Top-scorer Bradley Wright-Phillips is likely to be restored to the starting line-up in Benson's place.
On-loan left-back Matt Fry returned to the squad in midweek and is pushing for a starting berth, but centre-back Gary Doherty will remain sidelined with a hamstring problem.
Midfielders Joe Anyinsah and Johnnie Jackson will also be missing with ankle and Achilles injuries respectively.
Powell himself will serve a one-match touchline ban after being charged with misconduct by the FA following comments he made after last Saturday's 1-1 draw with Tranmere.
Source: PA
Source: PA