unity - Move ball based on direction of force?

I'm trying to make a ball that will move in the direction I push it from, and later pull it to me based on where the player is standing.

using UnityEngine;
using System.Collections;

public class BallForce : MonoBehaviour {

    public float thrust;
    public Rigidbody rb;

    // Use this for initialization
    void Start () {

        rb = GetComponent ();
    }

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

        if (Input.GetMouseButton (0))
            rb.AddForce (transform.forward * thrust);
    }
}

This seems to work, but I'm not sure how I get it to move based on the position of the player. How would I do this?