Winger Plummer will definitely not be fit after twisting his ankle on Friday.
Stimson is likely to make several changes to his starting line-up following the defeat on Saturday which left him "devastated".
The Kent club are without a win in their last eight games and are level on points with fourth-bottom Brighton.
Curtis Weston is set to return in midfield after being rested against the Bees, while Danny Jackman, Dennis Oli and Mark McCammon are pushing for recalls.
Simon King (ankle), Garry Richards (conjunctivitis) and Jacob Erskine (ankle) are all unavailable.