Kane's main problem, is that unlike other Spurs players, like Modric, Bale and Berbatov, he has no way of forcing a move, as he can't even bluff that he'd go on strike or not give 100%. He's so goal hungry and determined to break records, that if Levy decides he's not selling for anything less than a ridiculous fee, then Kane will still give everything, week in week out. Of course that's how it should be with all players, but it usually isn't and clubs don't like unhappy players around. But the chances of Kane causing trouble or not giving his all, are close to zero.