Captain Justin Whittle hurt his shoulder in training on Thursday, and is thought to be touch and go for tomorrow's game.
Ian Goodison (knee) and Matt Wicks (hamstring) will still be missing, leaving caretaker manager Billy Russell with few options in central defence.
Mark Greaves is a certain starter if he has recovered from a calf injury sustained at Leyton Orient last week. Ben Petty could make the switch from right-back to partner the 27-year-old in the centre of defence, with Mike Edwards coming back into the side at full back.
The only other options are moving Jason Van Blerk to the middle, or recalling Nick Mohan.
Elsewhere, while Lawrie Dudfield (hamstring) and Gary Bradshaw (back) are probably still out, Rodney Rowe should be fit to be in contention up front, along with Gary Alexander, Kyle Lightbourne, Adrian Caceres and Theo Whitmore, who is back after a neck injury.
Whitmore could be the matchwinner, says Billy Russell, but his place in the side isn't certain. He faces competition from Richard Sneekes, Adrian Caceres and David Norris for an attacking midfield spot.
Russell said: "Theo trained yesterday and looked sharp. He's got a chance of playing but it's a matter of weighing up all the options and deciding which is the side best suited to picking up three points.
"We'll be going for goals and when you look at our position in the table - and how many games we've got to play - then we've got to look to beat Darlington. It's a very big game for us."
Expected line-up (4-4-2): Musselwhite; Edwards, Petty, Greaves, Van Blerk; Williams, Johnsson, Sneekes, Philpott; Alexander, Lightbourne.
Subs from: Glennon, Whittle, Mohan, Holt, Matthews, Beresford, Norris, Whitmore, Caceres, Dudfield, Rowe.