Stir together the Worcestershire sauce, olive oil, hot sauce, garlic and pepper. Add the duck breasts and toss well to coat. Cover and marinate in the refrigerator for at least 30 minutes to overnight.
Preheat a barbecue for medium-high heat.
Barbecue the duck to desired doneness, about 5 minutes per side for medium-well, depending on the size of the breast and the temperature of the barbecue.