Letang was down for almost 5 minutes real time as trainer Chris Stewart and Penguins Dharmesh Vyas attended to him. As you can tell he clearly skated off very gingerly with assistance needed.
Letang has had a number of concussions in the past and also a stroke in 2014. It remains to be seen the extent of his injuries, thus the need to keep him in the hospital overnight, obviously.
Shane Doan, the player who hit Letang. showed remorse in his comments after the game to the Arizona Republic, saying:
"That’s awful. When it happened, I could tell the way he went into the boards was awkward."
"I just went to make sure I got a piece of him so he couldn't jump by me. ... We have to finish our check on him."
You never ever want to see anybody like that, especially a guy of his caliber and obviously everything he's went through."
Contrition aside, that doesn't help the Penguins moving forward without their #1 defenseman who was having a Norris Trophy caliber season.
It's a wonder the ref- who was right there and quickly blew the whistle to stop play and get Letang treatment- didn't see this late hit as a penalty, but further discipline could come down from the league in form of a suspension. That too won't help the Pens any at this point, as they await the status of their best defenseman with the playoffs starting in just over 2 weeks time.