Duclair has also played in the NHL for the Arizona Coyotes, Chicago Blackhawks, Columbus Blue Jackets, Ottawa Senators, Florida Panthers, San Jose Sharks and Tampa Bay Lightning.

[6] The Lions then advanced to the Telus Cup, where Duclair scored two goals in their bronze medal match win over the Vancouver North West Giants.

[10] He impressed head coach Alain Vigneault during the Rangers' 2014 training camp, but was not able to appear on their opening night roster until the team was under their 50-contract limit.

General manager Glen Sather traded defenseman Steven Kampfer and forward Andrew Yogan to the Florida Panthers in exchange for Joey Crabb in order to accommodate a roster position for Duclair.

[11] He made his NHL debut on October 9, 2014, playing on a line with J. T. Miller and Lee Stempniak for a 3–2 Rangers victory over the St. Louis Blues.

[16] Although Vigneault and the Rangers were initially hesitant to send Duclair back to the Remparts, as he would have to remain there until the conclusion of their 2014–15 season,[17] he was too young to play in the American Hockey League (AHL) and was returned to his junior team on January 5, 2015.

[21] On March 1, 2015, while playing with the Remparts, Duclair was traded to the Arizona Coyotes (along with John Moore and two draft picks) in exchange for Keith Yandle and Chris Summers.

[23] This was due to the fact that during the 2015 World Junior Ice Hockey Championship, Duclair and Domi both showed visible chemistry and were key components in leading Canada to gold.

[26] On January 19, 2017, Duclair was demoted to the team's American Hockey League (AHL) affiliate, the Tucson Roadrunners, due to a lack of production.

[27] On January 10, 2018, Duclair was traded (alongside defenceman Adam Clendening) to the Chicago Blackhawks in exchange for forwards Richard Pánik and Laurent Dauphin.

On July 1, 2023, due to salary cap considerations, Duclair was traded by the Panthers to the San Jose Sharks in exchange for Steven Lorentz and a fifth-round selection in 2025.