The game against Columbus was not even five minutes old before Chicago's Adam Boqvist had to leave the ice.
A shot by Zac Dalpe went straight to the covering Swede, who got the puck in the face.
He took his hand over his mouth and nose to the replacement booth but was soon forced to leave as well and could not return to play.
Coach Jeremy Colliton told the Chicago Star Tribune after the match that Boqvist showed signs of a concussion and will be investigated further.
The match was still goalless when Boqvist left it, but then the goals rolled in. The team was followed to 3-3 after regular time and the match was only decided in the second minute of extra time, when Brandon Hagel sprinted in a counterattack 4-3 behind Joonas Korpisalo in the Columbus goal.