Complex sentence: But if one wants to add an element into a sorted array, O (N) time may be required, but it is in the worst case to update the data structure (e.g., when an insertion into the head of the array is required).
Split into simpler sentences: But if one wants to add an element into a sorted array, O (N) time may be required. This, however, is the worst case complexity to update the data structure (e.g., when an insertion into the head of the array is required).