Jack Hughes left Tuesday's game against the Seattle Kraken after a hard hit into the boards in the closing minute of the first period.
Hughes did not return to the ice in the second period.
After the game, Lindy Ruff said Hughes is "day-to-day" and will be reevaluated on Wednesday.
Hughes appeared to have suffered an upper-body injury when he was dragged down by Jeremy Lauzon and fell to the ice, seemingly leading with the head/shoulder area.
Hughes stayed on the ice for a few seconds before skating off under his own power into the locker room.
Less than two minutes into the period, Mason Geertsen - making his NHL debut - took matters into his own hands, and dropped the gloves with Lauzon. The two continued throwing punches even with two referees in between them. They both received 10-minute game misconducts.
In Friday night's season opener, the 2019 first overall pick scored two goals, including the overtime game-winner - he tossed his stick into the crowd in the celebration.