We know about Kamara, McGinn and Tielemans," he said at his pre-Salzburg press conference.
“Kamara is a long time, I think he’s not going to play this season. McGinn, more or less, is 6-8 weeks out, and Tielemans is 8-10 weeks out.
“After those updates of those players, we need to see how we can manage centre midfielders in the matches we are going to play."
Emery added: "Ross Barkley is coming back in a few days. He has been training individually but he's so close to joining us.
And we have George Hemmings. He is a young centre-midfielder, but he's training with us, knowing, tactically, everything we need. He has huge potential and maybe it's a moment he can help us.
“This is the reason, always, we are accepting the injured players because something can happen, and we must be ready.”
In addition to the aforementioned trio, Emery revealed Andres García will be sidelined in the short-term after picking up an injury.
And while Leon Bailey has returned to the club and Tammy Abraham has signed from Besiktas, the pair are not eligible to feature on Thursday night.
Emery said: “After the centre midfielders, Andres García is out for three weeks. He has a hamstring injury, a small injury.
“I think the other players, they are well, they are fine for tomorrow.
“Of course, they are not involved in the Europa League, Leon Bailey and Tammy Abraham. They are out, but we have enough players.”
