1Heat gas or charcoal grill. In small bowl, stir together garlic, sage, oil, salt and pepper. Rub garlic mixture over pork.
2Carefully brush oil on grill rack. Place pork on grill over medium heat. Cover; cook 35 to 40 minutes, turning occasionally, until meat thermometer inserted into center of pork reads 155°. Remove from grill; cover with foil and let stand 5 minutes until thermometer reads 160°F.
3To serve, cut pork across grain into thin slices. Garnish with additional fresh sage leaves if desired.