Complex sentence: Brian is the oldest of the famous Sutter brothers who played in the NHL, the oldest brother Gary, who some say was the best hockey player out of all the brothers never did play in the NHL as he never pursued a hockey career.
Split into simpler sentences: Brian is the oldest of the famous Sutter brothers who played in the NHL. The oldest brother Gary, who some say was the best hockey player out of all the brothers never did play in the NHL since he never pursued a hockey career.