Add Meatballs: Place the frozen meatballs into a slow cooker.
Make the Sauce: In a bowl, whisk together the ketchup, brown sugar, apricot preserves, and Worcestershire sauce until smooth.
Combine: Pour the sauce evenly over the meatballs and toss to coat.
Cook: Cover and cook on HIGH for 2–3 hours or LOW for 4 hours, stirring halfway through.
Serve: Keep warm in the slow cooker for serving. Serve with toothpicks, over rice, or on slider buns.