Defender Frampton has been sidelined for a fortnight with a calf injury but is back in training and close to a return.
Striker Harris missed Tuesday night's win over Southend with the groin strain he suffered against Oldham at the weekend and will also have a late fitness check.
On-loan Peterborough forward Shaun Batt will hope to keep his place in the starting line-up following his debut goal against the Shrimpers.
Another frontman, Gary Alexander, remains a long-term absentee following his recent heel operation.
The Lions are unbeaten in their last four games and moved into the play-off places following their midweek victory.