What prompted the Penguins to swap Radim Zohorna for Valtteri Puustinen in the lineup?
Mike Sullivan was beaming Friday. Sure, the Pittsburgh Penguins coach was happy his team defeated the Vegas Golden Knights at home, 5-2, that evening. But what really invigorated Sullivan was the NHL debut of rookie forward Valtteri Puustinen. Primarily deployed on the third line, the diminutive Puustinen (5-foot-9, 183 pounds)...