Add the Worcestershire sauce, olive oil, minced garlic, hot sauce, and black pepper to a large bowl. Whisk until thoroughly combined.
Add the duck breast halves and turn them several times until completely coated with the marinade.
Cover the bowl and refrigerate for at least 30 minutes. For deeper flavor, marinate for several hours or overnight.
Preheat an outdoor grill to medium-high heat and lightly oil the grill grates if necessary.
Remove the duck from the marinade, allowing the excess liquid to drip back into the bowl. Discard the used marinade.
Place the Grilled Wild Duck Breast portions on the hot grill and cook for approximately 5–7 minutes per side, adjusting the cooking time according to their thickness.
For food safety, USDA guidance for poultry is an internal temperature of 165°F (74°C), measured in the thickest part.
Transfer the duck breasts to a clean plate and let them rest for about 5 minutes before slicing.
Slice across the grain and serve warm.