Preheat your grill to medium heat.
In a food processor, pulse the salmon until finely chopped but not pureed. Transfer to a large bowl.
Add breadcrumbs, green onions, parsley, egg, Dijon mustard, garlic powder, salt, and black pepper to the bowl with the salmon. Mix until well combined.
Form the mixture into small balls, about 1 to 1.5 inches in diameter.
Lightly brush the grill grates with olive oil to prevent sticking. Place the salmon balls on the grill and cook for about 4-5 minutes on each side, or until cooked through and golden brown.
While the salmon balls are grilling, prepare the creamy avocado sauce. In a bowl, mash the avocado and mix in Greek yogurt, lime juice, minced garlic, salt, and pepper until smooth and creamy.
Serve the grilled salmon balls warm with the creamy avocado sauce on the side for dipping.