David McGoldrick, Tyrone Mings and Cole Skuse return to the side and Luke Hyam, Tommy Smith and Kevin Bru all drop to the bench as Mick McCarthy makes three changes to the team which drew 1-1 at Derby a fortnight ago.
Skipper Luke Chambers moves to centre-half alongside Christophe Berra with Jonny Parr at right-back and Mings on the left.
In midfield, Teddy Bishop keeps his place in the centre of midfield with Skuse returning having been unwell for the game against the Rams. Paul Anderson will be on the right and Jay Tabb on the left.
McGoldrick, who missed out at Derby with a dead leg, returns either in a front two with Daryl Murphy or in the role between the lone striker and the midfield. There is no place in the 18 for returning midfielder Darren Ambrose, who signed a short-term deal on Thursday.
Former Blues skipper Carlos Edwards starts at right-back for Millwall but Lee Martin misses out with a knee ligament injury. Former Blue Ed Upson and one-time Town loanee Ricardo Fuller are on the bench.
Town: Gerken, Parr, Mings, Chambers (c), Berra, Skuse, Bishop, Tabb, Anderson, McGoldrick, Murphy. Subs: Bialkowski, Smith, Bajner, Hyam, Bru, Henshall, Sammon.
Millwall: Forde, Edwards, Dunne, Beevers, Malone, Powell, Williams, Woolford, McDonald, Easter, Ranegie. Subs: King, Briggs, Webster, Upson, Onyedinma, Gueye, Fuller.