On-loan winger Harley missed Saturday's 1-1 draw against Preston with a neck injury and faces a late fitness test.
Fellow midfielder Dean Bowditch returned to the squad after recovering from a groin problem but had to be content with a place on the bench.
Goalkeeper David Martin remains sidelined with a back problem while veteran midfielder Alan Smith serves the final game of his four-match ban.
Chelsea loanee Patrick Bamford remains at his parent club as he continues to receive treatment on a hamstring injury.
The Dons have drawn their last three matches in npower League One and are without a win since their famous FA Cup victory at QPR back in January.