I can say as an Arsenal fan if KDB plays I'd bite your hand off for a draw. If he isn't playing then I think there's a much bigger chance of us winning.
With KDB in the team and both sides playing to their maximum then City win. If he's not playing and both play to their maximum then that's maybe not the case.
If also worry about walker being unfit assuming Martinelli is fit as he is lighting fast and gives Arsenal an offensive out ball. Walker could neutralise that, not sure whoever comes in has the same ability to counter that threat.
Regardless I'd still bite your and off for a draw but if KDB isn't there then I'd expect it, if he is there then I'd hope for it if that makes sense!