Place chicken breasts in the bottom of your slow cooker.
Cover chicken completely with salsa.
Cook on low for 6-8 hours. Depending on how much liquid is expelled during the cooking process, you may need to drain some liquid before the next step...shred chicken.
One hour before serving, chop the zucchini into bite-size pieces and add to the chicken mixture.
Drain the pineapple juice into a separate bowl. Add pineapple to the slow cooker and 3/4 cup of juice.
Serve on tortillas or with your favorite side dish!
