It sounds like we're unlikely to see Michael Duffy play. I read recently that Stevie Frail and the other coaches etc are treating him just like any of the other Development Squad, not a fringe player who just needs game time. They are still working on his best position and trying to get him to be more ruthless in front of goal. He apparently needs to do a bit of work on his shooting (especially with his left foot apparently).
Aiden Nesbitt scored a hat-trick against Rangers in the Youth Cup Final and he has appeared for the senior team already in friendlies so it would be nice to see him given a chance to run at ICT, however Nesbitt is on the small side and playing against what can be a VERY physical Inverness team may not be the best thing for him!
O'Connell made a return from injury in that cup final game as well, he's been out for some time with a hernia that needed to be operated on. Callum Waters played LB while Kieren Tierney playe LW, either of them could be brought into the first team to replace Izzy.
At CB, I think VVD will be back but I think Mulgrew will also play now that he has returned from injury.
Personally I think Deila should go with something like:
Fasan
Fisher - VVD - Mulgrew - Waters/Tierney
Brown - Bitton
GMS - Johansen - Armstrong
Griffiths
Subs: Gordon, Scepovic, Tierney/Waters, O'Connell, Matthews, Forrest, Nesbitt