Heat oven to 400°F. Line muffin pan with paper baking cups or lightly grease.
Drain and rinse blueberries in cold water. Set aside.
Stir together water, oil, eggs and banana until combined. Add muffin mix and stir until blended.
Gently fold in blueberries.
Scoop batter into muffin pan, filling cups ⅔ full.
Bake 18-22 minutes or until golden brown. Cool 5 minutes, gently loosen and remove from pan.