Hofer, 18, was selected by the Blues in the fourth round, 107th overall, of the 2018 NHL Draft.
Last season, the 6-foot-3, 161-pound goaltender played in 19 regular season games with the Broncos, posting an 8-3-1 record along with a 2.61 goals-against average and a .914 save-percentage. The Winnipeg, Manitoba native also appeared in two postseason games, helping the Broncos capture the WHL Championship.