Michalek has played in two games since Feb. 12. He tried to return and play through the injury, recording assists against the Toronto Maple Leafs on March 6 and the New York Rangers on March 8, but hasn't been in the lineup since.
In 15 games this season, Michalek has two goals and 10 points. He led the Senators with 35 goals last season and was third with 60 points.
The Senators' top-two scorers from last season, forward Jason Spezza and defenseman Erik Karlsson, also have been out of the lineup with long-term injuries.
It's a date that's been circled on my calendar, so it's kind of nice to have it here and get it over with (Thursday). This is a little bit of the closing of the book on the move. That's kind of how I'm looking at it.
— Stars forward Jason Spezza on returning to Ottawa for the first time to face the Senators