Porter made knee-on-knee contact with Booth midway through the first period of Vancouver's 6-0 rout of the Avalanche on Tuesday night. The Canucks forward was circling with the puck toward the slot when the collision occurred.
"This is not a full body check during which there was some knee-to-knee contact," NHL disciplinarian Brendan Shanahan said in a video statement. "Nor is it a kneeing penalty resulting from the attacking player making a sudden, evasive move just prior or simultaneous with contact."
Porter was assessed a major penalty and a game misconduct for the play. Booth sprained his right MCL on the hit and is expected to miss four to six weeks.
"What is especially troubling about this hit is the distance Porter travels with his knee extended in this position," Shanahan added. "While it can be argued that Porter's history and the situation of the game would suggest that there was no malicious intent, it still was an extremely reckless hit that caused a severe injury."
This is the first suspension of Porter's four-year career in the NHL.
Porter will forfeit US$18,378.36 to the Players' Emergency Assistance Fund.
Porter will miss Thursday's game in Calgary, Friday's game in Edmonton, as well as the Avalanche's home-and-home series with San Jose on Dec. 13 and 15.
He will be eligible to return Dec. 17 when Colorado hosts Washington.