MacKenzie drilled Ekman-Larsson from behind, resulting in a possible concussion for the Phoenix Coyotes' defenseman after his head hit the boards with a fair amount of force. MacKenzie has no prior disciplinary history, however.
This was simply not a good hit by MacKenzie. Ekman-Larsson was basically prone before and as MacKenzie went to deliver the blow. The distance between Ekman-Larsson and the boards also likely contributed to the damage done to the Coyotes blueliner. Just a bad situation all around.
Had MacKenzie simply eased off there or minimized the contact, he wouldn't be sitting the next three games.