Gustavsson was reassigned to AHL Belleville on Sunday, Ian Mendes of the Athletic reports.
This is a straight goalie swap for the Senators, as 21-year-old Mads Sogaard was promoted to the big club to replace Gustavsson. The 23-year-old Swede has struggled at the NHL level this season, with a 3-11-1 record, 3.78 GAA and .886 save percentage.