Michalek has 23 points in 22 games this season, emerging as San Jose's third-leading scorer in just his second full NHL campaign. The 21-year-old Czech forward was injured in Anaheim last week when his arm was bent awkwardly against the boards while chasing a puck, forcing him to miss the Sharks' last two games.
The move was retroactive to Nov. 22, so Michalek could return as early as Wednesday's game at Minnesota, the Sharks' second stop on a four-game road trip beginning Tuesday in St. Louis.
San Jose already is playing without winger Jonathan Cheechoo, who led the NHL last season with 56 goals. He has missed four games since his leg was injured in a goal-mouth scramble in Colorado, but could return as early as Tuesday.
The Sharks' 34 points put them third overall in the NHL despite the absence of two of their top six forwards. San Jose has won four of its last five games.
To replace Michalek, the Sharks recalled defenceman Josh Gorges from their AHL affiliate in Worcester.