His reasons for joining include being close to his brother William and having the chance to play the Canadian style of hockey.

[7] Nylander was called up to the NHL for the first time on 3 April 2017, to play in a game against the Toronto Maple Leafs.

[9] Nylander suffered a lower-body injury in mid-September during the Buffalo Sabres' first prospect game, causing him to miss the rest of the training camp and the beginning of the 2017–18 AHL season.

[15] On 9 July 2019, Nylander was traded by the Sabres to the Chicago Blackhawks in exchange for fellow first-rounder Henri Jokiharju and opted to wear sweater no.

[17] He injured his left knee in the first round of the 2020 Stanley Cup playoffs, and missed the entire 2020–21 season while recovering from surgery.

[21] Instantly joining the Blue Jackets, Nylander made his debut with Columbus in a 4–2 victory over the New York Rangers on 25 February 2024,[22] and recorded his first NHL hat trick in a 6–3 win against the Vegas Golden Knights on 4 March 2024.

[23] In an elevated offensive role with the Blue Jackets, Nylander responded in notching a career best 11 goals through just 23 games to close out the season.

As a free agent from the Blue Jackets at the conclusion of his contract, Nylander was unable to secure an NHL deal and opted to sign a one-year AHL contract with the Toronto Marlies of the AHL, affiliate to the Toronto Maple Leafs on 28 July 2024.

[29] He spent the majority of his youth in the United States where his father played for a multitude of NHL teams, and spending the summers in Sweden.