Rotating Sphere With Some Lag

Hello. I'm hoping someone can help me think through this. I'm trying to create a sphere, inside which will be the player's first person view. I want to make the sphere follow the player's view, but lag behind a bit. So if the player looks up, the sphere will rotate up a little slower. The added difficulty is that I'm trying to do this on a Google Cardboard setup. I can make the sphere a child of the camera, but then it just tracks perfectly without allowing me to add the lag. Any help would be appreciated!