warning CS0414: The private field `ChangeToSecondForm.playerToBeChangedFrom' AND `ChangeToSecondForm.playerChangingTo' is assigned but its value is never used

I feel incredibly dumb not knowing what to do. I have tried figuring this out since yesterday and still proves to be out of my grasp of solving this. It seems to me that the private game objects that I had set for myself is clearly (at least to me) been assigned but it continues to say that it is not. Is it the way I set my script up? How can I remember next time not to trip over myself on this problem that seems deceptively easy? Any advice would be very appreciated.

 using UnityEngine;
 using System.Collections;
 
 public class ChangeToSecondForm : MonoBehaviour 
 {
     private static ChangeToSecondForm instance = null;
     public static ChangeToSecondForm Instance
     {
         get {return instance; }
     }
 
     private GameObject playerToBeChangedFrom;
     private GameObject playerChangingTo;
 
     public Transform secondFormDisplay;
     public int maxEnergy = 100;
     public int currentEnergy;
     private float energyOriginalXScale;
 
     // Use this for initialization
     void Start () 
     {
         currentEnergy = 0;
         energyOriginalXScale = secondFormDisplay.localScale.x;
         playerToBeChangedFrom = GameObject.FindGameObjectWithTag ("PlayerCharacter");
         playerChangingTo = GameObject.FindGameObjectWithTag ("PlayerCharacterSecondForm");
     }
     
     // Update is called once per frame
     void Update () 
     {
         if (currentEnergy <= 0) 
         {
             secondFormDisplay.GetComponentInChildren<Renderer>().enabled = false;
         }
         
         if (Input.GetButtonDown ("TransformToSecond") && (currentEnergy == 100)) 
         {
             Debug.Log("Q has been pressed");
             currentEnergy = 0;
         }
     }
 
     public void GatherEnergy(int energyGathered)
     {
         Debug.LogError ("Got Energy from dead enemy.");
         
         currentEnergy += energyGathered;
 
         if (currentEnergy > 100) 
         {
             currentEnergy = 100;
         }
 
         secondFormDisplay.localScale = new Vector3(energyOriginalXScale * (currentEnergy/maxEnergy), secondFormDisplay.localScale.z, secondFormDisplay.localScale.z);
     }
 }