The striker made his full debut in Monday's 3-2 win at Portsmouth but is cup-tied for the third-round tie having already appeared in the competition for Peterborough.
Another recent arrival, striker Matty Fryatt, is eligible following his permanent move from Leicester and could make his first start after stepping off the substitutes' bench to score on his debut at Portsmouth.
Robert Koren is back in contention following illness and could step in for Mclean but manager Nigel Pearson will be without fellow midfielder Tom Cairney, who is sidelined after burning himself on scolding water at home.
Defender Liam Rosenior sits out the second of a three-game ban, goalkeeper Vito Mannone has returned to parent club Arsenal due to a thigh injury and winger Richard Garcia has undergone knee surgery.
Pearson could hand a late fitness test to full-back Paul McShane, who is struggling with a shoulder injury.