Alex replaced Fraser Minten on the top unit at the club's full morning skate on Wednesday.
The Toronto Maple Leafs are set to feature two Nylanders on their top power-play unit on Wednesday when they face the Florida Panthers at Amerant Bank Arena in Sunrise, Florida.
Alex Nylander, fresh off his Leafs debut, will step into the top unit, joining his brother William Nylander, Morgan Rielly, John Tavares, and Mitch Marner.