Colborne, 23, played five regular-season games for the Maple Leafs last season, collecting two penalty minutes. The 6-foot-5, 213-pound center also skated in his first two NHL playoff games.
In the American Hockey League, he played 65 games for the Toronto Marlies, where he had 14 goals and 42 points. He tied for first on the Marlies in assists (28) and power-play goals (seven). In 16 NHL games, all with the Maple Leafs, he has one goal, five assists and six penalty minutes.
He split the 2012-13 season playing for the Norfolk Admirals and Portland Pirates in the AHL. In 52 games, the native of Portage la Prairie, Manitoba had seven goals, 16 points and 118 penalty minutes. The 6-4, 219-pound forward played 16 games for the Marlies in the 2009-10 season, during which he had six goals and 10 points.