Colborne was drafted 16th overall in the 2008 Entry Draft and was always viewed as a project. While his size and skating made him worthy of a first round selection, The Hockey News described his play as "indifferent" and his skills as "undeniable".
After two solid seasons at the University of Denver, in 2010-11, Colborne made the full-time transition to the AHL's Providence Bruins where he posted a fairly lacklustre 26 points in 55 games and was subsequently traded to the Maple Leafs. Colborne had more success with the Marlies to close out the 2010-11 season (16 points in 20 games) and spent the first couple months of the 2011-12 season among the AHL leaders in points, earning an invitation to the AHL All-Star Game. Colborne's point pace slowed to a crawl to close out the season as injuries (he was forced to skip the All-Star Game) and the loss of linemate Joey Crabb seemed to seriously affect his game.
All of this looks like a fairly standard progression for a prospect taken in the middle of the first round and yet, at 22 years old, Colborne is no spring chicken. Even before he was drafted, his production never seemed to match what many saw as his underlying talent. First, it was explained away by his family's affluence; he didn't, some claimed, have the same pressures to succeed as most of his peers. Last season, the blame lay with injuries and a late growth spurt that has kept his metabolism high and prevented him from adding weight to his lanky frame. At some point though, you need to deliver on your promise.