Spring has missed the last two matches with a calf problem and will be handed a late fitness check.
Fellow midfielder Adam Chambers is a definite absentee with a shin injury which is expected to keep him out for another fortnight, but boss Russell Slade has an otherwise fully-fit squad to choose from.
Defender Terrell Forbes will hope for a recall after dropping to the bench at MK Dons in midweek, while striker Jonathan Tehoue is pushing to start after climbing off the bench to hit the winner.
Orient head into the tie in fine form, having lost just once in their last 20 matches and on the back of three straight wins which have lifted them to within three points of the play-off places.
Source: PA
Source: PA