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.
This is a great day for me. This is something I've been thinking about for a long time. This is a great opportunity that the St. Louis Blues organization, (owner) Tom Stillman and Doug Armstrong are giving me and trusting me in doing...This is going to be a great challenge for me.
— Martin Brodeur, after announcing his retirement as an NHL player and becoming a senior adviser with the Blues on Thursday