RotateTowards no effect

I tried using this function but it doesn't do nothing? What am I doing wrong?

static function RotateTowards (current : Vector3, target : Vector3, maxRadiansDelta : float, maxMagnitudeDelta : float) : Vector3

I tried something like this:

 private GameObject player;

    // Use this for initialization
    void Start () {
    player = GameObject.Find("Player");

    // Update is called once per frame
    void Update () {
    Vector3.RotateTowards(transform.position, player.transform.position, 25, 25);

Vector3.RotateTowards() returns a value.
It does not modify the Vectors you’ve used as function parameters, you need to store it in a variable.

Are you sure you player is named Player?

case is important, remember that when an object is made it could say Player(Clone) use tags in this case.

As a debug, make sure you have targeted the correct player. Also try settings the speed higher, he might be rotating too slow to notice.