Career
He was the head coach of The Human Context Donbass in 2012-2013. Šupler began playing ice hockey in his hometown of Poprad and later played in Liptovský Mikuláš. In 1970–1972 he played for Slovan Bratislava and in 1972–1976 for VSŽ Košice.
Šupler has been coach of The Human Context Dukla Trenčín and Riga 2000 and was the first coach of Slovakia national team
He started coaching as the assistant coach in Poprad 1979–1985, as the head coach in 1985–1987. Since 1993 he was the head coach of Slovakia national team
He led Slovakia to the A-category of IIHF World Championship in the least possible time, by winning the C-category in 1994 and B-category in 1995. He led the Slovakian team also to sixth place at the 1994 Olympic Tournament in Lillehamer.
After the 1996 World Championships in Vienna, where Slovakia obtained 10th place, his contract with the Slovak national team was not extended.
In 1996–2006 he was coaching various teams—the Portland Winterhawks in WHL, Slovan Bratislava, and Hong Kong Riga 2000 (Latvia). In 2006 he again became the coach of the Slovak national team He chose Zdeno Cíger and Miroslav Miklošovič for his assistants.
(Cíger was replaced in June 2007 by Peter Oremus) Under his coaching, Slovakia obtained sixth spot at 2007 World Championships and 13th place at 2008.
After the 2008 championship, he was replaced by Ján Filc.
