 He then played for the AHL Cincinnati Mighty Ducks for the 2004–05 season and posted a season best save percentage of 0.924 and GA of 2.07 with 10 SO, while winning 25 games.For 2005–06, Cassivi returned to the AHL Hershey Bears and the Washington Capitals and posted his most wins during the regular season, 34, en route to winning the AHL Calder Cup.Cassivi earned the Calder Cup Playoff MVP award, the Jack A. Butterfield Trophy, for his strong play in net during the series.