Rask, who has inherited the starting job in Boston due to Tim Thomas's sabbatical, has been playing with HC Plzen of the Czech Extraliga. He has performed tremendously until now, with a 93.24 save percentage in seven starts.
Rask blanked Slavia Praha for one period before coming out of the game.
The severity of the injury is uncertain, but it is cause for concern in Boston, as Rask missed significant time down the stretch last season, also suffering from a groin injury. Following the game, Rask told Czech reporters:
"I slightly pulled my groin, it is not serious. I had groin problems last year so i took little rest just for precaution"
If the Finnish netminder is severely hurt, Anton Khudobin is next in line for promotion. Khudobin has only played seven career games but has shined in each of them. His only appearance for Boston last season was a 44-save victory over the Ottawa Senators.
Khudobin, currently playing in the KHL for Atlant Moscow Oblast, is talented but very unproven. If Rask is unavailable when the lockout is lifted, fans and perhaps the Bruins' brass will beg for two time Vezina Trophy winner Tim Thomas to return.
One other option may be veteran free agent Dwayne Roloson, who led the Tampa Bay Lightning to the Eastern Conference finals two years ago.
The Bruins selected Belleville Bulls (OHL) goalie Malcolm Subban in the first round of the 2012 draft, but despite the prospect's tremendous potential, he is not expected to see NHL ice this year.
Rask was expected to be an elite option in net for the Bruins. His health will be crucial to the Bruins championship hopes.
More information on Rask's injury is sure to follow in the coming days.