There are apparently four teams that have inquired in the past: those being Minnesota, Colorado, NY Islanders, and New Jersey. It is unknown how a trade will actually work, as all four teams are right against the cap, like Toronto.
A new team that might have emerged recently, is apparently Chicago. The Blackhawks have a lot of cap space, and not a lot of talent on the roster, so Nylander would be a great fit.
Nylander is in the last year of his $6.96 million deal, and many Toronto fans grow more and more worried the longer he remains unsigned. Nylander set a career high in points last year with 87 points in 82 games. He also scored 40 goals for the first time in his career.