BUFFALO, N.Y. (AP) — The NHL is looking into the circumstances that led to Tampa Bay Lightning forward Pontus Holmberg hurting his left arm when he crashed shoulder-first into an unlatched penalty box door on Monday night.

What You Need To Know

Tampa Bay Lightning forward Pontus Holmberg injured his left arm when he crashed shoulder-first into an unlatched penalty box door on Monday night

“Not good,” coach Jon Cooper said when asked about the player’s status, before abruptly ending his postgame news conference

Holmberg lost his balance and fell awkwardly into the penalty box door, which pushed open upon impact before the penalty box official slammed it shut

A league spokesman otherwise had no further comment in response to Lightning coach Jon Cooper questioning whether the penalty box operator should be fired over what happened in the third period of the Lightning’s 4-2 loss at Buffalo.

“I don’t know who’s working the penalty box over there, but I don’t know if they should keep their job after what happened there, like, leaving the door open,” Cooper said.

“That could have hurt anybody on either team,” he added. “Those are just dangerous situations, so a little frustrated on my part.”

Holmberg, who did not return, was spotted having his left arm in a sling following the game.

“Not good,” Cooper said when asked about the player’s status, before abruptly ending his postgame news conference.

“Should be fired,” Lightning forward Brandon Hagel said upon leaving the locker room and overhearing a discussion over what happened.

Holmberg was injured following what appeared to be a clean open ice check from Buffalo’s Peyton Krebs. Holmberg lost his balance and fell awkwardly into the penalty box door, which pushed open upon impact before the penalty box official slammed it shut.

Holmberg was checked at the same time the official was opening the door to release Buffalo’s Zach Benson, whose roughing minor was expiring.

Benson’s penalty expired with 7:20 left in the period, and play stopped with 7:16 on the clock with Holmberg lying in pain on the ice.

Cooper’s frustration stemmed in part from losing another player to injury, with the Lightning already missing captain Victor Hedman (personal leave) as well as Hagel (lower body), Scott Sabourin (lower body) and Anthony Cirelli (undisclosed).