He's exceptional for his age, as I'm sure he's aware. I suspect he think's he's got a chance of playing for Man Utd, and I wouldn't doubt that.
I think he's also aware that he won't be challenging De Gea any time soon without already proving himself in the PL. Judging by how much he thrives on the crowd, I can't see him wanting to warm a bench or play in the 23s either.
Based on that, if he carries on the way he is for us, I imagine he'll attract PL suitors next season, I'd guess on loan, meaning I reckon our best chance of keeping him, even if only on loan again, would be going up.
I do worry sometimes that the same might apply to O'Connell.