Nylander announced Monday that he will sport No. 88. He previously wore No. 29 and No. 39 with the Leafs.
Nylander also used No. 88 during his time with Modo Hockey in the Swedish Hockey League, prior to coming to the NHL.
The 23-year-old is looking to bounce back this season after struggling in an abbreviated 2018-19 campaign that was delayed because of his contract negotiations as a restricted free agent. Nylander played 54 games with Toronto last season, recording seven goals and 27 points.