I think he's got bags of ability, but does he have the attitude?
Last year, 4 months on from a Champions League final, he was showing so little effort for a man who developed him into an International Football, and someone who would be on the radar of most of the big teams around the world. Fast forward to now, and he's still not found form, Jose has forced him out (yes, Jose is stubborn, but how many times has been "wrong" in these scenarios?).
Then you've got the idea that would Tottenham really sell him to us, a potential future rival? I can't see it myself. Big talk of PSG, and if I was Alli, I'd be biting their hands off.