The Sabres made the move before a deadline Friday that would have prevented Pysyk from playing in the minors during the 16-day break that begins Feb. 9.
Pysyk had missed Buffalo's past two games with an undisclosed injury. He has a goal and five assists in 42 games this season.
To fill his spot, the Sabres recalled defenceman Chad Ruhwedel from Rochester.
Buffalo (13-29-7) plays at Columbus (26-20-4) on Saturday.