But Senators owner Eugene Melnyk isn't any happier about losing the defending Norris Trophy winner, especially since it involved a player with a history of questionable play.
"To have him taken out by a goon is unconscionable," Melnyk told TSN on Friday. "Whether it was accidental, or whether it was reckless, or whether it was intentional, to me it doesn't matter.
"It's something that never should have happened. This player should never be playing in this league. It's a league for elite players."
Cooke has been suspended five times in his career but has not been disciplined since March 2011, when he was suspended 10 games, plus the first round of the playoffs, for a hit to the head of the New York Rangers' Ryan McDonagh.
Cooke since has said he has changed the way he plays the game, but Melnyk does not believe that.
"I don't buy any of that garbage," Melnyk told TSN. "Five times? No, we're No. 6? How about seven and eight? At what point do you say, 'You know what? Maybe he's not changed.' You do this enough times, don't try to convince me or anybody else. People are way too intelligent. The guy gets suspended five times. That's how many times he's been suspended, never mind how many times he's not been suspended.
"I'm just shocked that that organization employs that type of individual."
The Penguins told ESPN.com on Thursday that they would not defend Cooke if they thought his was a dirty play.
"I feel horrible for Erik Karlsson; I feel bad for Ottawa," Pittsburgh general manager Ray Shero said. "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."
Melnyk also disagreed with the NHL's decision not to discipline Cooke.
"The league has its own way of working," Melnyk told TSN. "They have their job, we have our job. At the end of the day, they are responsible for this. This is a reflection on the NHL. But saying that, if they're right, they're right. We have a different view at this point.
"Over the coming weeks, we'll get to the bottom of it. ... You can't see it on camera, that's why you can't blame the league for this or anyone else. On camera you look at it, but when you look at it logically, you've got a blade that has to cut through socks, has to then cut through skin, fat, muscle, everything that protects the tendon, then cuts 70 percent of the tendon."
Senators GM Bryan Murray said Thursday that Karlsson is expected to have a full recovery after surgery repaired the "clean cut," but Karlsson's season is done.
Murray added that Karlsson felt he "got directed and got cut with a skate that shouldn't be where it was."
"You will forget about guys like him (Cooke) in a year or two because they won't be playing in the league," Melnyk told TSN. "He's done it to us; he's done it to others. If he thinks it's cool to be the tough goon, then that's his business, but people aren't going to put up with him. We're certainly not going to put up with him. ... He's on a watch list now. Everybody should know it.
"You certainly don't belong in this league, and the faster you're gone, the better."