Jack Eichel had to be helped off the ice on Wednesday after suffering an an ankle injury on the eve of the Buffalo Sabres' season opener.
The 19-year-old star, who led the team in goals last season as a rookie, was evidently in pain and could not put any weight on his left leg as he was helped off the rink.
Sabres coach Dan Bylsma confirmed the setback in a media conference after practice, saying Eichel was in "a lot of pain" and will undergo further evaluation.
"I was just trying to get the puck, and we got tangled," Sabres team-mate Zemgus Girgensons told the Buffalo News. "He just fell awkward."
The second overall pick in last year's NHL entry draft lived up to his considerable advance billing as a rookie, with 24 goals and 32 assists in 81 games. He played for Team North America in last month's World Cup of Hockey.
Buffalo open their season on Thursday against the Montreal Canadiens.