The players missed training last night on account of a high temperature and feeling unwell and they have been confined to their rooms in Baku.
Ireland manager Stephen Kenny was unsure this morning if they would be able to train tonight, although he indicated that Idah was in better health than Knight at this juncture.
Idah would be certain to start tomorrow night if fit, while Knight would be a strong contender as his absence was felt last month. He started both games in the June camp.
"Adam and Jason both came down with a fever and strong temperature. They passed all the tests, they received negative tests from their antigen tests and PCR tests," said Kenny, speaking in Azerbaijan this morning.
"They are all fine, it's just probably from the travel. Adam has a high temperature and is confined to his room. Jason, who is as tough as anything, just has a very high temperature and is unwell.
"We have to see if they are well enough to train today. They were not well enough to train (last night).
"They are still confined to their rooms at the moment and Adam is maybe further down the line than Jason. It came on Jason yesterday before training so his is a bit later.
"We will have to see. The match is not until tomorrow although you do have to name the (matchday) squad tonight. It's probably an old fashioned travel thing."
Idah said last month that he was waiting on the call for his second Covid jab. Knight missed the September games through injury and is rated highly by the manager.
"These are things that you cannot control," said Kenny, "Jason is very mature for his age, he has tremendous energy, has incredible fitness levels and is tactically good.
"He is a very focused young individual but you obviously cannot play if you're not right. So we will have to see."