The hit sent Boyle into the dasher boards and knocked him unconscious. He was carried off the ice on a stretcher.
Boyle stayed overnight for treatment in a St. Louis hospital before returning to San Jose. The Sharks have released no information on the nature or extent of his injuries.
Lapierre will lose $28,205.15 in pay because of the hit. He has already served one game of the suspension while he awaited a hearing with the NHL's Department of Player Safety.
Brendan Shanahan, the NHL's senior vice president of player safety, noted in his decision that Boyle had stumbled before the hit and had put himself in a vulnerable position.
However, Shanahan added that while the stumble might "mitigate some of the responsibility for the hit, it doesn't erase it entirely."