Arsenal boss Mikel Arteta admits Gabriel Jesus is battling with a knee injury.
The striker is struggling to overcome the setback and has missed the past four games.
Arteta said: "We could not resolve it as quickly as we wanted and he had a small reaction in training again.
"We didn't want to take any more risks because he has been out for quite a while and he is a player that we need at his best. We decided to give him a few more days."
On Thomas Partey facing Newcastle on Saturday, he added: "We have another session today. He's been out for many, many months now. We need to really nail the timing of when he has enough in the tank to compete. But I think he's very close."