Mysterious boy appears to Locke & Sawyer, says "You can't kill him"

As Locke and Sawyer are making their way through the jungle, the mysterious boy appears again, but this time he's not bloody. Sawyer sees him first and then Locke chases the boy as he runs away.

Locke trips and falls, then looks up to see the boy looking down at him. The boy says "You know the rules. You can't kill him." Locke screams his classic catch phrase at him "Don't tell me what I can't do" as the boy walks away.

So who is this boy? The way he sauntered away from Locke, he seems like Jacob. There are also some visual similarities between he and Jacob. It could certainly be someone else though. What do you think?