It took less than three minutes for the first questionable hit of the Eastern Conference final to unfold Friday night in Game 1.
Lightning winger Ryan Callahan was assessed a five-minute major for boarding Kris Letang at 2:50 of the first period, and could face supplemental discipline from the NHL Department of Player Safety.
Letang was retrieving a puck in the corner with his back to the winger when Callahan approached at full speed and drove Letang face-first into the boards.
Letang fell limp on the ice for several seconds, and in one replay angle appeared to lose consciousness.