With about four minutes left in a 5-2 loss to the New York Islanders on Sunday, Eichel appeared to hurt his neck after being checked into the end boards by Casey Cizikas.
The Sabres are presently mired in an eight-game losing streak, with their latest having come Tuesday against the Philadelphia Flyers. Their .333 points percentage is tied with the Detroit Red Wings for second-last in the NHL (the Ottawa Senators are last at .328).
The 24-year-old Eichel has found scoring difficult this season, despite being one of the league's better snipers. He's potted just two goals in 21 games, and is in the midst of a 13-game scoring drought.
Buffalo hosts the Pittsburgh Penguins on Thursday night at 7 p.m. ET.