In small bowl, mix butter, chopped sage, salt and pepper. Starting at leg end of chicken, gently separate skin (do not peel back) from chicken breasts using fingers, being careful not to tear or puncture skin. Rub half of sage butter under skin to cover chicken breasts; replace skin. Rub remaining sage butter on outside of chicken breasts and thighs. Fold wings of chicken under back. Tie or skewer drumsticks together. On rack in shallow roasting pan or 13x9-inch pan fitted with rack, place chicken, breast side down. Cover loosely with foil. Insert ovenproof meat thermometer so tip is in thickest part of inside thigh muscle and does not touch bone.