According to the Ottawa Sun, the injury occurred during offseason training last month in Montreal.
Michalek, 27, is coming off the best season of his NHL career, when he set a career-high with 35 goals and totaled 60 points for just the second time in eight seasons. His 10 power-play goals also tied for the team lead.
The groove of being behind a bench is going to be interesting at first, but thank God we have a few exhibition games to get rid of those cobwebs. Overall the excitement of it all and the freshness and coming back refreshed, all those things are going to be assets. If [the players] come ready to give their best effort in practice and games, good things are going to happen. I'm always looking for results. It's not always on the scoreboard. It's winning and building something.
— Bryan Trottier on making his return to coaching as an assistant with the Sabres