Oilers' Zack Kassian knocked unconscious in 'scary' preseason fight with Canucks' Zack MacEwan
Kassian's helmetless head hit the ice midway through the fight, causing him to lay motionless for a few moments
Kassian's helmetless head hit the ice midway through the fight, causing him to lay motionless for a few moments
Mueller was transported to a nearby hospital but had movement in his extremities