Complex sentence: Unfortunately he was involved in a controversial match against his former team the Toronto Croatia, where during the derby match Zupan was involved in a confrontation with the match official, and as a result the league banned Zupan for the rest of the season.
Split into simpler sentences: Unfortunately he was involved in a controversy match against his former team the Toronto Croatia. Where during the derby match Zupan was involved in a confrontation with the match official, and as a result the league banned Zupan for the rest of the season.