Preheat your grill to medium-high heat.
In a mixing bowl, combine the diced pineapple, cream cheese, mozzarella cheese, green onions, teriyaki sauce, garlic powder, onion powder, salt, and pepper. Mix well until all ingredients are evenly incorporated.
Carefully slice a pocket into each chicken breast, making sure not to cut all the way through.
Stuff each chicken breast with the pineapple mixture, securing the opening with toothpicks if necessary.
Brush the outside of the chicken breasts with olive oil and season with additional salt and pepper.
Place the stuffed chicken breasts on the grill and cook for about 6-7 minutes on each side, or until the internal temperature reaches 165°F.
Remove the chicken from the grill and let it rest for 5 minutes before serving.