If you will be planting another ‘Naval’ orange tree it would be a good idea not to plant it in the same hole where the original tree died. Some diseases, like foot rot disease, can be carried in the soil and planting a healthy tree in the same hole where one died due to foot rot would increase the chances that the new tree might develop the disease as well.

When selecting a new tree, choose one that has healthy green leaves and does not have a lot of roots emerging from the drain holes in the pot (which would indicate that the tree was root bound).