The fear for the worst involving Tuukka Rask has been confirmed.

On Thursday just hours prior to their contest with the Canucks, the Bruins confirmed that Rask has suffered a concussion following his collision with Anders Bjork during Wednesday’s practice at Warrior Ice Arena. Rask is currently under the NHL’s concussion protocol and is out indefinitely.

“I don’t think anyone wants to run [over] the goalie whether it’s your first, second or third string,” head coach Bruce Cassidy said about the Bjork-Rask collision during net front drills on Wednesday. “It’s incidental contact on a kind of hard drill where we’re trying to build in more net action and more net drive, and that’s the spillover from that sometimes.”

Anton Khudobin, who gets his second start of the season tonight, will take over the team’s No. 1 spot in place of Rask for the foreseeable future. The Bruins also recalled Zane McIntyre from Providence to serve as the backup behind Khudobin.

In four games this season, Rask is 1-3-0 with a 3.30 goals against average and .882 save percentage. His only win of the season came on opening night against the defending Western Conference champion Nashville Predators.

Certainly a tough break for the Bruins, who will have the likes of David Backes returning to the lineup on Thursday after a bout of diverticulitis. Adam McQuaid, who left during Sunday’s game against the Golden Knights after contact with former Bruin Colin Miller, should be in as well, while Patrice Bergeron (lower-body) is a game-time decision.

The Bruins also announced that they placed Ryan Spooner on IR after suffering a right groin injury in Vegas on Sunday.