The National Hockey League has already decided that there will no hearing and no supplemental discipline for Penguins forward Matt Cooke regarding the injury to Ottawa Senators defenceman Erik Karlsson.

Cooke was tangled up with Karlsson near the puck along the boards on Wednesday night when his skate blade cut the left achilles of the Norris Trophy-winning blueliner.

The Senators said that Karlsson will require surgery and will be out indefinitely. According to TSN Hockey Insider Darren Dreger, Karlsson's tendon wasn't completely cut, but the best case scenario for Karlsson to return is upwards of four months.

The league said on Thursday that the Department of Player Safety has reviewed the incident and that Brendan Shanahan has spoken with both general managers.

"I feel horrible for Erik Karlsson, I feel bad for Ottawa," Penguins GM Ray Shero told ESPN.com on Thursday morning. "It's a bad feeling. But I can't rationalize where that was a dirty play or anything with intent. Our fan base knows how it feels to lose a star player. It's emotional. I know how it feels like. It's just very unfortunate. I would not be defending Matt Cooke if I thought it was a dirty hockey play."

The 34-year-old Cooke has a long history of suspensions from the NHL, several of which have been for hits to the head. He has been banned from play five times during his career, most recently in March, 2011 for an elbow to the head of New York Rangers defenceman Ryan McDonagh. For that incident, Cooke was suspended for the remainder of the season and the playoffs, a total of 17 games.