Prior to being selected by the Toronto Maple Leafs, Korostelev posted 53 points (23G, 29A) during his draft year with the Sarnia Sting. In his final rankings, Bob McKenzie ranked him at 69, so this could only help his cause as a late-round steal.
Furthermore, his scouting report on elite prospects made Maple Leaf fans salivated even more:
A deft skater that plays a skill-based, puck-possession game. Very creative with the puck: can let loose an accurate bullet, utilize his stickhandling ability to create chances, or make a seeing-eye pass to an open teammate.