Leading scorer DJ Campbell, who bagged 10 goals in 17 games on loan with Town, has returned to QPR for the time being at least and so Michael Chopra is set to come in.
Goalkeeper Stephen Henderson and defender Bradley Orr have also been denied permission to feature by their parent clubs, West Ham and Blackburn respectively.
That means Scott Loach is likely to get the nod between the sticks while manager Mick McCarthy is poised to bring in Elliott Hewitt at right-back.
Midfielder Andy Drury remains missing due to the illness which forced him to miss the 3-0 New Year's Day defeat at home to Brighton, with defender Luke Chambers also a doubt having broken his nose in training.
New loan signing Patrick Kisnorbo has been cleared to play having arrived on a month-long deal from Leeds on Thursday.