The move was made Wednesday, a day after leading goal scorer Thomas Vanek suffered what the team is calling an upper body injury in a 3-1 win at Montreal. Vanek is expected to miss at least a week.
Kassian is a hard-hitting forward who was selected in the first round of the 2009 draft by Buffalo. He's in his first pro season and had three goals and three assists in an 18-game stretch with the Sabres earlier this season.
In 28 games in Rochester, he has 11 goals and 11 assists.
