How can I link a GameObject instance to a script variable in a Prefab using the editor?

I have an enemy that is supposed to track the player. I can drag the player instance to the target variable on an instance of my enemy’s script but as soon as I make my enemy a prefab, the link is broken. I can then drag the player prefab (but not the instance) to the enemy script, but the enemies then target the prefab at 0,0,0. Is there a way to assign the player instance to the script variable on the prefab?

I’d like to avoid finding the player instance using code since I want to apply this method in other similar situations such as referencing the player instance from a UnityEvent on a prefab pickup script that should be more generic than just grabbing the player instance.

As far as I know it is not possible to assign instances to prefabs.

Imagine creating a new scene and placing the prefab in that scene. The prefab would still be referencing an instance of the player, but the instance does not exist!