How to attach a prefab to a script that is added dynamically

Hey,

I created a script that is added into my game is added to my player Game Object using the AddComponent() method. The thing is the script needs a prefab(ShockWave) and I'm not sure how to give it the prefab other than having to tell the script what it needs before runtime. I had always figured that I could just add the prefab into the field shown in the image below but that doesn't seem to work for me as it just comes up null.

Does anyone have a solution for this? Also was I correct in thinking I could add my prefab into this field?