The Brazil international, who was forced off with a knee injury during last weekend’s 2-2 draw with Liverpool, will be in contention for a game at St James’ Park provided he completes a successful training session on Friday.
Gunners boss Mikel Arteta is also awaiting news on Ben White, who lasted the full 90 minutes against Arne Slott’s Reds but has not trained since.
William Saliba is in line to return to the top flight after a one-match ban to ease Arsenal’s defensive woes, but Ricardo Calafiori and Takehiro Tomiyasu remain sidelined, in addition to captain Martin Odegaard.
Speaking about Gabriel, Arteta said: “We have training today. If he can complete that, he will be available.
“He hasn’t had any training yet but if he can do that today he will be available for the team.
“Rizzi and Martin are definitely out.
“We don’t know about Ben yet because he hasn’t trained yet. He couldn’t train, he couldn’t come on, so let’s wait and see if he’s available or not.”