Kessel has led the Maple Leafs in scoring the past six seasons, but was traded along with minor-league center Tyler Biggs, defenseman Tim Erixon and a second-round pick in the 2016 NHL Draft for forwards Kasperi Kapanen and Nick Spaling, defenseman Scott Harrington and a first- and third-round draft pick in 2016.
Having not yet hired a general manager, Maple Leafs president Brendan Shanahan orchestrated the trade, which he said started at the draft last week in Florida.
"I had said at the end of the season there were going to be changes," Shanahan said. "For whatever reason we had a lot of talented individuals on this team, but as a group, the core group, it hadn't worked. This is about winning. Phil is certainly a very talented player and we knew changes had to come."