Internationally, Nemisz was a member of Team Canada's silver medal-winning squad at the 2010 World Junior Ice Hockey Championships.

He then went on to score a goal and six assists in the 2009 Memorial Cup as the Spitfires defeated the Western Hockey League's Kelowna Rockets to win the national junior championship.

[4] He finished the season in Windsor with 70 points in 51 games, helping the Spitfires to win their second consecutive OHL championship while also capturing the 2010 Memorial Cup.

[5] Nemisz turned professional in the 2010–11 season and was assigned to the Flames' American Hockey League (AHL) affiliate, the Abbotsford Heat.

[9] While recovering from the injury, Nemisz joined the OHL's Oshawa Generals as a volunteer video coach during the team's 2015 run to the Ontario Hockey League and 2015 Memorial Cup championships.