 On 31 January 2015, the Red Wings assigned Gustavsson to the Grand Rapids Griffins for a conditioning assignment.During his conditioning stint, Gustavsson started two games for the Griffins, making 29 saves on 31 shots in a 4–0 loss to the Milwaukee Admirals on 31 January, and stopping 30-of-31 shots during a 3–1 win against the Toronto Marlies on 4 February.On 4 September 2015, Gustavsson was invited to training camp by the Boston Bruins on a Professional Try Out.