error CS1061: Type `UnityEngine.Networking.PlayerController' does not contain a definition for `transform' and no extension method `transform' of type

using System.Collections;
using UnityEngine;
using UnityEngine.Networking;

public class LevelManager: MonoBehaviour {

public GameObject currentCheckpoint;
	
private PlayerController player;

// Use this for initialization
void Start () {
	
	
}

// Update is called once per frame
void Update () {
	
}

public void RespawnPlayer()
{
	Debug.Log ("Player Respawn");
	player.transform.position = currentCheckpoint.transform.position;
}

}

Line 19 use

player.gameObject.transform.position = currentCheckpoint.transform.position;

instead.