The Maple Leafs have traded forward Phil Kessel to the Penguins, a source confirmed to ESPN.com's Pierre LeBrun.

The Penguins are sending the Maple Leafs forwards Kasperi Kapanen and Nick Spaling, defenseman Scott Harrington and a first-round draft pick in return, a source said. Additional players could be involved, as well.

Kessel, 27, collected 25 goals and 36 assists this past season for the Leafs, his sixth season for the team.