I think a back up for Eriksen, a CM (that could be the same person), a back-up striker for Kane (since it seems Llorente is one year too old), and ideally one more young centreback.
I think all 3 need to be kids, not "right now" signings, especially the CM/centreback choices, as we'll need them for the long haul, as Vertonghen, Alderweireld, and Dembele age out of the squad. We've got Sanchez, Foyth, maybe CCV, and Winks as the long-term solutions, but will need enough depth to keep them fresh, so we need more guys to add to them.