From MapleLeafs.com:
This year’s prospect group will consist of 57 players; 33 forwards, 20 defencemen and four goaltenders. All nine members of the Maple Leafs’ 2015 draft class will be in attendance, including the fourth-overall selection, Mitch Marner. Kasperi Kapanen, acquired in a trade with the Pittsburgh Penguins on Wednesday, will also take part in the camp.
(Petes defenceman Cameron Lizotte was one of the youngest members of the 2015 Draft class, and some expected him to be a late pick last Saturday; Aiden Jamieson a 19 year old London Knight defenceman.