A recurrence of a hamstring injury has kept Petrucci out of the last two matches but the on-loan Manchester United midfielder could return to the squad.
Teenage left-back Kgosi Ntlhe could also come back into the reckoning after a couple of run-outs for the reserves following a broken ankle.
Gaby Zakuani has been nursing a shoulder problem but Posh boss Darren Ferguson will ask the centre-half to play through the pain barrier, possibly with the aid of an injection.
Striker Tyrone Barnett, who had a loan spell at Ipswich towards the end of 2012, continued his return to full fitness with a run-out for the reserves this week.
He played 70 minutes on Wednesday afternoon, less than 24 hours after making his comeback from three months out with a knee injury as a substitute in the 2-2 draw with Charlton.
Ferguson insists Barnett will be in the squad again against the Tractor Boys. He said: "Tyrone will definitely be involved whether it's as a substitute or a starter. His attitude since he returned to the club has been excellent."