Striker Benson serves the final game of a three-match ban following his red card at Colchester on New Year's Day.
Lee Martin was this week recalled from his loan spell by Ipswich but Powell still has plenty of options in attack in Joe Anyinsah, Akpo Sodje, Pawel Abbott and Nathan Eccleston.
Liverpool loanee Eccleston came on as a substitute in the 2-2 draw at Sheffield Wednesday last week and could make his full debut at The Valley.
Chris Solly is back in training after a long-term ankle injury but fellow defender Kelly Youga is out for the season with a knee problem.
Source: PA
Source: PA