Ka dib markii uu ka qeyb galay xerada tababarka ee Kings ee 2016, Černák waxaa dib loogu magacaabay xerada tababarka ee xidhiidhka American Hockey League (AHL), Ontario Reign. In kasta oo uu ciyaaray ciyaar cajiib ah heerka AHL, haddana waxaa dib loogu soo celiyay heerka hoose si uu u ciyaaro xilli ciyaareedkii labaad ee kooxda Ontario Hockey League (OHL) ee Erie Otters xilli ciyaareedkii 2016-17. 26 Febraayo 2017, Boqorrada waxay ku beddeleen Černák (oo ay weheliyaan Peter Budaj iyo 2017
doorashada wareega toddobaad) ee Tampa Bay Lightning iyada oo lagu beddelay goolhayaha Ben Bishop iyo doorashada wareega shanaad ee 2017.