Zirkzee is clearly a player who relies on understanding and being understood by his teammates. He is the opposite to the likes of Garnacho who is inherently quite selfish and therefore looks good in a dysfunctional team - because he is happy to just go it himself.
I am relatively convinced that if you put Zirkzee into a well drilled system, with players that he synergies well with, he has the potentially to be excellent. Not 30-goals or world class, but a really effective contributor. I see him like a Firmino.
Right now, players are still mastering Amorims system, we have a lot of injuries and a lot of areas where we need to strengthen. For a player like Zirkzee who relies on intricate linkup play and one touch football, this is a bigger issue than it is to a lot of other players.