Whisk together whiskey, pineapple juice, BBQ sauce, minced garlic, Worcestershire sauce, salt and pepper. Pour over chicken and let marinate 4-6 hours.
Remove chicken from marinade and grill over medium heat for 10 to 12 minutes, flip and cook for an additional 8-10 minutes or until chicken is cooked throughout.
Brush with additional BBQ sauce before removing from grill, if desired.