Losing Milan Michalek to a mysterious lower body injury in the pre-game warmup was a rough way for the Senators to start their night in City of Bridges.

Little did they know things would get much, much worse.

During the second period of a game against the Pittsburgh Penguins Wednesday night, star defenceman Erik Karlsson suffered a lacerated Achilles that will require surgery after he was hit by Matt Cooke. Karlsson likely is finished for the season.

The Senators went on to lose 4-2 at the Consol Energy Center.

"Obviously, I feel terrible about it," Cooke told Dave Molinari of the Pittsburgh Post Gazette. "I'm not trying to do that, obviously."

But Senators GM Bryan Murray was furious over how the Karlsson injury happened.

As time ticked down in the second period, Karlsson went to the boards in his own end to retrieve a loose puck while being pursued by the Penguins shift-disturber.

A moment after arriving, he went down in a heap, obviously in pain, yelling at the closest referee. Replays showed that Cooke's skate came down hard on the back of Karlsson's left, lower leg.

Did he intentionally get stomped by Cooke? Senators brass in attendance seemed to think so. Yet no penalty was called.

"It's Matt Cooke," Murray said. "Just look at the replay. That's all you have to do."

Captain Daniel Alfredsson was asked whether he thought it was intentional.

"I saw it quick," he said. "I don't know if it's intent to injure. I don't know why you would hit somebody like that, in that situation. But I can't tell if it's intent to injure."