After failing to stay with Calgary after the 2002–03 season, Szuper was picked by the St. Louis Blues and played in the 2003–04 season in their ECHL affiliate, the Peoria Rivermen.
Szuper je tako postal prvi Madžar, ki je bil del aktivne NHL postave za kako tekmo, a ga uradni NHL register ne priznava, ker na nobeni tekmi ni nastopil.