Vancouver Canucks rookie centre Elias Pettersson will undergo an MRI after suffering a right knee injury on Thursday night in Montreal.
The Canucks tweeted there is no timetable for their top scorer's return.
WATCH | Pettersson injured in loss to Canadiens:
Elias Pettersson appeared to suffer a leg injury in Vancouver's 2-0 loss to Montreal on Thursday. 0:51
Pettersson suffered the injury after getting tied up with Montreal rookie Jesperi Kotkaniemi in the second period of the Canadiens' 2-0 win on Thursday night.
The Swedish-born Pettersson easily leads all NHL rookies with 42 points, 17 ahead of Colin White of the Ottawa Senators.
The Canucks conclude a six-game road trip on Saturday night against the Toronto Maple Leafs.
And while it doesn't appear Vancouver's phenom will play against the Leafs, like much of the hockey world, Toronto coach Mike Babcock has been taken aback by Pettersson's rookie season.
'Smarter than everybody else'
"He's smarter than everybody else, so he can stand still and create space," Babcock said after the Leafs practised on Friday. "You can say lots of things about him — he doesn't look like he's that strong. He just has the puck the whole time.
"Everybody keeps backing off, so he has space and he can shoot it and he can pass it and he sees it. He looks like a real player to me."
Babcock said he was especially impressed by Pettersson's performance in Ottawa against the Senators on Wednesday when the Swede scored a hat trick in the Canucks' 4-3 overtime win.
"Dominant, dominant, dominant player," said the coach. "Had the puck all the time. I don't know why. But some of those guys … you ask Mitch [Marner] why he has the puck all the time.
"I don't know, they're just smarter than everybody."