Manager Karl Robinson told the media at his pre-match press conference that the defensive duo, both of whom have been sidelined through injury, will play a part in the FA Cup third-round replay.
Centre-half MacKenzie recently returned from a three-month absence following hip surgery, making substitute appearances in the league win at Notts County on New Year's Day and the goalless draw against his old club at Hillsborough nine days ago.
Full-back Otsemobor, who was the injury-time hero in the second round against AFC Wimbledon, has not featured since the 3-2 defeat at Brentford on December 8 due to a groin problem.
Robinson also revealed that he has concerns about the fitness of on-loan midfielder Ryan Harley (groin) and striker Ryan Lowe (illness) ahead of Tuesday night.
Meanwhile, Izale McLeod, who made his first appearance for the Dons in Saturday's 1-1 home draw with Bury since returning to the club, is cup-tied having played in the competition for former club Portsmouth.
Should Robinson's side get through they will set up a fourth-round tie at QPR, who they faced in last season's third round, taking the Premier League side to a replay at Loftus Road where they were narrowly beaten 1-0.