Midfield is the most crucial part of the team selection that Unai Emery must get right.
If the midfield is not right then Arsenal will lose, that we have learned at huge cost since Emery took charge. The defence needs help and the forwards need service, two areas in which the midfield is pivotal.
It is an almost certainty that Granit Xhaka and Matteo Guendouzi will start and so, in reality, there is just the one place up for grabs.
It does not need an expert to question the inclusion of Xhaka but that is Emery for you. For some reason, the Spaniard has a lot of faith in the Swiss international.
Gunedouzi deserves his place because he is in form and hopefully he will be more productive than usual.
I suspect that Joe Willock will not be selected and that a more creative individual will be given the final starting berth.
Dani Ceballos looks a good shout to be a starter. The alternative is Mesut Ozil but I doubt The German will even be in the squad.
So, the chances are that Emery will have a midfield trio of Guendouzi, Xhaka and Ceballos.
Personally, I would have prefered Ceballos, Torreira and Willock but as usual, Emery will go with the players he trusts.
Same as the situation with the defence, if Emery gets his midfield selections wrong today and loses it will be his own fault.
Too often the wrong team has been selected by the 43-year-old. The pressure will increase signficantly if Palace win today. Getting the team selection right will help avoid that scenario.