Darren Ferguson is waiting on an update on the fitness of attacker Siriki Dembele who is struggling with a knee problem.
The Ivorian was not in the squad for Sunday's 3-0 FA Cup win over Dover Athletic, with the Posh boss revealing the player was rested as he strives to recover from tendonitis.
Dembele came off the bench for the final half hour of the recent 1-0 Sky Bet League One win over Burton Albion, and then played in a friendly arranged for last midweek.
But a knee issue he has been suffering flared up during that game, and the player is now a doubt for this week's Leasing.com Trophy clash with Ipswich Town on Wednesday night, as well as Saturday's league trip to Portsmouth.
Asked why Dembele wasn't involved at the weekend, Ferguson said: "He has a bit of tendonitis on his knee.
"He played in the game we had on Wednesday, and did very well, scoring a really good goal.
"But he had to come off and he was quite sore, so the decision was to that he is going to go and see somebody about it.
"It is nothing serious, but we felt the rest would do him some good, which it has done.
"Once he has seen the specialist then we can make a decision about whether or not we inject it, and if we do then it means he will probably miss Wednesday (v Ipswich) and the Portsmouth game.
"Alternatively, the rest will have done its job and he can crack on again, but him missing out Sunday was just an opportunity to get some rest into that knee, because he has been having problems for quite a while now."
Another player who looks likely to miss this week's games is Frazer Blake-Tracy, who hobbled off in the second half of Sunday's game with an ankle injury.
And Ferguson feels it could be a serious one.
"I think it's a bad one, but we will have to assess it," said the Posh boss.
"When you see a player down for that long, and the physio said straight away that he had to come off, it's not looking good."